Golf balls having at least one layer formed from a plasticized acid copolymer composition

ABSTRACT

The present invention is directed to multi-layer golf balls including a layer formed from a relatively soft or low modulus HNP composition and a layer formed from a relatively hard or high modulus HNP composition. Optionally, the soft (or low modulus) HNP composition and/or the hard (or high modulus) HNP composition is plasticized or is replaced with a different plasticized acid copolymer composition.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/588,317, filed Dec. 31, 2014, which is a continuation-in-part of U.S.patent application Ser. No. 14/145,593, filed Dec. 31, 2013, now U.S.Pat. No. 9,427,630, the entire disclosures of which are herebyincorporated herein by reference.

Parent application Ser. No. 14/145,593 is a continuation-in-part of U.S.patent application Ser. No. 13/692,583, filed Dec. 3, 2012, which is acontinuation of U.S. patent application Ser. No. 13/169,753, filed Jun.27, 2011, which is a continuation of U.S. patent application Ser. No.12/795,295, filed Jun. 7, 2010, now U.S. Pat. No. 7,967,701, which is acontinuation of U.S. patent application Ser. No. 12/125,306, filed May22, 2008, now U.S. Pat. No. 7,731,607, which is a continuation-in-partof U.S. patent application Ser. No. 11/972,240, filed Jan. 10, 2008, nowU.S. Pat. No. 7,722,482, and U.S. patent application Ser. No.11/738,759, filed Apr. 23, 2007, now U.S. Pat. No. 7,517,289, which is acontinuation-in-part of U.S. patent application Ser. No. 11/304,863,filed Dec. 15, 2005, now U.S. Pat. No. 7,211,008, the entire disclosuresof which are hereby incorporated herein by reference.

Parent application Ser. No. 14/145,593 is also a continuation-in-part ofU.S. patent application Ser. No. 13/758,041, filed Feb. 4, 2013, whichis a continuation of U.S. patent application Ser. No. 13/329,398, whichis a continuation of U.S. patent application Ser. No. 12/697,368, filedFeb. 1, 2010, now U.S. Pat. No. 8,079,920, which is a continuation ofU.S. patent application Ser. No. 12/125,260, filed May 22, 2008, nowU.S. Pat. No. 7,654,916. U.S. patent application Ser. No. 12/125,260 isa continuation-in-part of U.S. patent application Ser. No. 11/694,007,filed Mar. 30, 2007, now U.S. Pat. No. 7,452,290, which is acontinuation of U.S. patent application Ser. No. 11/304,962, filed Dec.15, 2005, now U.S. Pat. No. 7,207,903. U.S. patent application Ser. No.12/125,260 is also a continuation-in-part of U.S. patent applicationSer. No. 12/048,003, filed Mar. 13, 2008, now abandoned. U.S. patentapplication Ser. No. 12/125,260 is also a continuation-in-part of U.S.patent application Ser. No. 12/048,021, filed Mar. 13, 2008, now U.S.Pat. No. 8,357,059. The entire disclosure of each of these references ishereby incorporated herein by reference.

Parent application Ser. No. 14/145,593 is also a continuation-in-part ofSer. No. 13/584,167, filed Aug. 13, 2012, which is a continuation ofU.S. patent application Ser. No. 13/164,233, filed Jun. 20, 2011, whichis a continuation of U.S. patent application Ser. No. 12/125,320, filedMay 22, 2008, now U.S. Pat. No. 7,963,862, which is acontinuation-in-part of U.S. patent application Ser. No. 11/738,759,filed Apr. 23, 2007, now U.S. Pat. No. 7,517,289, which is acontinuation-in-part of U.S. patent application Ser. No. 11/304,863,filed Dec. 15, 2005, now U.S. Pat. No. 7,211,008, the entire disclosuresof which are hereby incorporated herein by reference. U.S. patentapplication Ser. No. 12/125,320 is also a continuation-in-part of U.S.patent application Ser. No. 11/972,259, filed Jan. 10, 2008, now U.S.Pat. No. 7,753,810, the entire disclosure of which is herebyincorporated herein by reference.

FIELD OF THE INVENTION

The present invention is directed to golf balls comprising a multi-layercore and a cover, wherein the core comprises a layer formed from arelatively soft HNP composition and a layer formed from a relativelyhard HNP composition, or a layer formed from a low modulus HNPcomposition and a layer formed from a high modulus HNP composition. Thepresent invention is not limited by which core layer is formed from thesoft (or low modulus) HNP composition and which core layer is formedfrom the hard (or high modulus) HNP composition, so long as both layersare present in the core of the golf ball. Optionally, the soft (or lowmodulus) HNP composition or the hard (or high modulus) HNP compositionis plasticized or is replaced with a different plasticized acidcopolymer composition.

BACKGROUND OF THE INVENTION

Conventional golf balls can be divided into two general classes: solidand wound. Solid golf balls include one-piece, two-piece (i.e., singlelayer core and single layer cover), and multi-layer (i.e., solid core ofone or more layers and/or a cover of one or more layers) golf balls.Wound golf balls typically include a solid, hollow, or fluid-filledcenter, surrounded by a tensioned elastomeric material, and a cover.

Golf ball core and cover layers are typically constructed with polymercompositions including, for example, polybutadiene rubber,polyurethanes, polyamides, ionomers, and blends thereof. Ionomers,particularly ethylene-based ionomers, are a preferred group of polymersfor golf ball layers because of their toughness, durability, and widerange of hardness values.

Golf ball compositions comprising highly neutralized acid polymers areknown. For example, U.S. Patent Application Publication No.2003/0130434, the entire disclosure of which is hereby incorporatedherein by reference, discloses melt-processible, highly-neutralizedethylene acid copolymers and process for making them by incorporating analiphatic, mono-functional organic acid in the acid copolymer and thenneutralizing greater than 90% of all the acid groups present. The use ofsuch compositions in various golf ball layers is disclosed. Also, U.S.Patent Application Publication No. 2005/0148725, the entire disclosureof which is hereby incorporated herein by reference, discloses ahighly-resilient thermoplastic composition comprising (a) an acidcopolymer, (b) a salt of a high molecular weight, monomeric organicacid; (c) a thermoplastic resin; (d) a cation source; and (e)optionally, a filler. The reference also discloses one-piece, two-piece,three-piece, and multi-layered golf balls comprising thehighly-resilient thermoplastic composition.

While various uses for highly neutralized acid polymers in golf ballshave been discovered, there continues to be a need in the industry tobroaden the applicability of highly neutralized acid polymers toparticular golf ball constructions having desirable spin, feel, and CORproperties. The present invention provides such golf ball constructionsthrough the use of a layer formed from a plasticized acid copolymercomposition.

SUMMARY OF THE INVENTION

In one embodiment, the present invention is directed to a golf ballcomprising a core and a cover. The core has an overall diameter of from1.40 inches to 1.60 inches and consists of a center, an intermediatecore layer, and an outer core layer. The center has a diameter of from0.50 inches to 1.50 inches and a center hardness (H) of from 20 Shore Cto 90 Shore C. The intermediate core layer has a surface hardness (I) of40 Shore C or greater. The outer core layer has a surface hardness (S)of from 20 Shore C to 90 Shore C. There is a hardness relationshipbetween H, S, and I wherein H<I and S<I. One of the core layers isformed from a first highly neutralized polymer and another of the corelayers is formed from a second highly neutralized polymer. At least oneof the first highly neutralized polymer composition and the secondhighly neutralized polymer composition comprises an acid copolymer ofethylene and an α,β-unsaturated carboxylic acid, optionally including asoftening monomer selected from the group consisting of alkyl acrylatesand methacrylates; a non-acid polymer selected from the group consistingof polyolefins, polyamides, polyesters, polyethers, polyurethanes,metallocene-catalyzed polymers, single-site catalyst polymerizedpolymers, ethylene propylene rubber, ethylene propylene diene rubber,styrenic block copolymer rubbers, alkyl acrylate rubbers, andfunctionalized derivatives thereof, an organic acid or salt thereof; anda cation source present in an amount sufficient to neutralize greaterthan 80% of all acid groups present in the composition. In a particularaspect of this embodiment, the intermediate core layer is formed fromthe first highly neutralized polymer composition, the outer core layeris formed from the second highly neutralized polymer composition, andthe material hardness of the second highly neutralized polymercomposition is less than the material hardness of the first highlyneutralized polymer composition. In another particular aspect of thisembodiment, the center is formed from the first highly neutralizedpolymer composition, the intermediate core layer is formed from thesecond highly neutralized polymer composition, and the material hardnessof the first highly neutralized polymer composition is less than thematerial hardness of the second highly neutralized polymer composition.In another particular aspect of this embodiment, the center is formedfrom the first highly neutralized polymer composition, the outer corelayer is formed from the second highly neutralized polymer composition,and the material hardness of the first highly neutralized polymercomposition is less than the material hardness of the second highlyneutralized polymer composition. In another particular aspect of thisembodiment, the center is formed from the first highly neutralizedpolymer composition, the outer core layer is formed from the secondhighly neutralized polymer composition, and the material hardness of thesecond highly neutralized polymer composition is less than the materialhardness of the first highly neutralized polymer composition.

In another embodiment, the present invention is directed to a golf ballconsisting essentially of a center, an outer core layer, an inner coverlayer, and an outer cover layer. The center has a diameter of from 0.50inches to 1.30 inches, a center hardness of 50 Shore C or greater, andis formed from a first highly neutralized polymer composition. The outercore layer has a surface hardness of 75 Shore C or greater and is formedfrom a second highly neutralized polymer composition. At least one ofthe first highly neutralized polymer composition and the second highlyneutralized polymer composition comprises an acid copolymer of ethyleneand an α,β-unsaturated carboxylic acid, optionally including a softeningmonomer selected from the group consisting of alkyl acrylates andmethacrylates; a non-acid polymer selected from the group consisting ofpolyolefins, polyamides, polyesters, polyethers, polyurethanes,metallocene-catalyzed polymers, single-site catalyst polymerizedpolymers, ethylene propylene rubber, ethylene propylene diene rubber,styrenic block copolymer rubbers, alkyl acrylate rubbers, andfunctionalized derivatives thereof, an organic acid or salt thereof; anda cation source present in an amount sufficient to neutralize greaterthan 80% of all acid groups present in the composition.

In a particular aspect of this embodiment, the inner cover layer has amaterial hardness less than the surface hardness of the outer corelayer, the modulus of the highly neutralized copolymer of the firsthighly neutralized polymer composition is at least 10% less than themodulus of the highly neutralized copolymer of the second highlyneutralized polymer composition. In another particular aspect of thisembodiment, the modulus of the highly neutralized copolymer of secondhighly neutralized polymer composition is at least 10% less than themodulus of the highly neutralized copolymer of the first highlyneutralized polymer composition.

In another embodiment, the present invention is directed to a golf ballcomprising a core and a cover. The core has an overall diameter of from1.40 inches to 1.62 inches and consists of a center, an intermediatecore layer, and an outer core layer. The intermediate core layer has asurface hardness less than the surface hardness of the center and thesurface hardness of the outer core layer. One of the core layers isformed from a first highly neutralized polymer and another of the corelayers is formed from a second highly neutralized polymer. At least oneof the first highly neutralized polymer composition and the secondhighly neutralized polymer composition comprises an acid copolymer ofethylene and an α,β-unsaturated carboxylic acid, optionally including asoftening monomer selected from the group consisting of alkyl acrylatesand methacrylates; a non-acid polymer selected from the group consistingof polyolefins, polyamides, polyesters, polyethers, polyurethanes,metallocene-catalyzed polymers, single-site catalyst polymerizedpolymers, ethylene propylene rubber, ethylene propylene diene rubber,styrenic block copolymer rubbers, alkyl acrylate rubbers, andfunctionalized derivatives thereof; an organic acid or salt thereof; anda cation source present in an amount sufficient to neutralize greaterthan 80% of all acid groups present in the composition. In a particularaspect of this embodiment, the center has a diameter of from 0.100inches to 0.750 inches is formed from the first highly neutralizedpolymer composition, the outer core layer is formed from the secondhighly neutralized polymer composition, and the material hardness of thefirst highly neutralized polymer composition is less than the materialhardness of the second highly neutralized polymer composition. Inanother particular aspect of this embodiment, the center has a diameterof from 0.125 inches to 0.750 inches is formed from the first highlyneutralized polymer composition, the outer core layer is formed from thesecond highly neutralized polymer composition, and the material hardnessof the second highly neutralized polymer composition is less than thematerial hardness of the first highly neutralized polymer composition.In another particular aspect of this embodiment, the center has adiameter of from 0.125 inches to 0.750 inches is formed from the firsthighly neutralized polymer composition, the intermediate core layer isformed from the second highly neutralized polymer composition, and thematerial hardness of the second highly neutralized polymer compositionis less than the material hardness of the first highly neutralizedpolymer composition. In another particular aspect of this embodiment,the center has a diameter of from 0.125 inches to 0.750 inches, theintermediate core layer is formed from the first highly neutralizedpolymer composition, the outer core layer is formed from the secondhighly neutralized polymer composition, and the material hardness of thefirst highly neutralized polymer composition is less than the materialhardness of the second highly neutralized polymer composition.

In the above embodiments, the highly neutralized composition comprisingan acid copolymer, a non-acid polymer, an organic acid or salt thereof,and a cation source optionally has one or more of the followingproperties:

-   -   (a) the acid copolymer does not include a softening monomer;    -   (b) the acid of the acid copolymer is selected from acrylic acid        and methacrylic acid;    -   (c) the non-acid polymer is an alkyl acrylate rubber selected        from ethylene-alkyl acrylates and ethylene-alkyl methacrylates;    -   (d) the non-acid polymer is present in an amount of greater than        50 wt %, based on the combined weight of the acid copolymer and        the non-acid polymer;    -   (e) the non-acid polymer is present in an amount of 20 wt % or        greater, based on the total weight of the highly neutralized        composition;    -   (f) the non-acid polymer is present in an amount of less than 50        wt %, based on the combined weight of the acid copolymer and the        non-acid polymer;    -   (g) the highly neutralized polymer composition has a solid        sphere compression of 40 or less and a coefficient of        restitution of 0.820 or greater;    -   (h) the highly neutralized polymer composition has a solid        sphere compression of 100 or greater and a coefficient of        restitution of 0.860 or greater;    -   (i) the organic acid salt is a metal salt of oleic acid;    -   (j) the organic salt is magnesium oleate;    -   (k) the organic salt is present in an amount of 30 parts or        greater, per 100 parts of acid copolymer and non-acid copolymer        combined; and    -   (l) the cation source is present in an amount sufficient to        neutralize 110% or greater of all acid groups present in the        composition.

In another embodiment, the present invention is directed to a golf ballcomprising a core and a cover. The core has an overall diameter of from1.40 inches to 1.60 inches and consists of a center, an intermediatecore layer, and an outer core layer. The center has a diameter of from0.50 inches to 1.50 inches and a center hardness (H) of from 20 Shore Cto 90 Shore C. The intermediate core layer has a surface hardness (I) of40 Shore C or greater. The outer core layer has a surface hardness (S)of from 20 Shore C to 90 Shore C. There is a hardness relationshipbetween H, S, and I wherein H<I and S<I. One of the core layerscomprises a first acid copolymer composition and another of the corelayers comprises a second acid copolymer composition. In a particularaspect of this embodiment, the intermediate core layer comprises thefirst acid copolymer composition and the outer core layer comprises thesecond acid copolymer composition. In another particular aspect of thisembodiment, the center comprises the first acid copolymer compositionand the intermediate core layer comprises the second acid copolymercomposition. In another particular aspect of this embodiment, the centercomprises the first acid copolymer composition and the outer core layercomprises the second acid copolymer composition. The acid copolymercompositions comprise an acid copolymer of ethylene and anα,β-unsaturated carboxylic acid, optionally including a softeningmonomer selected from the group consisting of alkyl acrylates andmethacrylates. At least one of the acid copolymer compositions is atleast partially neutralized such that at least 70% of all acid groupspresent in the composition are neutralized. At least one of the acidcopolymer compositions comprises a plasticizer in an amount of from 0.5wt % to 80 wt %, based on the total weight of the acid copolymercomposition. In a particular aspect of this embodiment, the plasticizeris selected from fatty acid esters.

In another embodiment, the present invention is directed to a golf ballconsisting essentially of a center, an outer core layer, an inner coverlayer, and an outer cover layer. The center has a diameter of from 0.50inches to 1.30 inches, a center hardness of 50 Shore C or greater, andcomprises a first acid copolymer composition. The outer core layer has asurface hardness of 75 Shore C or greater and comprises a second acidcopolymer composition. The acid copolymer compositions comprise an acidcopolymer of ethylene and an α,β-unsaturated carboxylic acid, optionallyincluding a softening monomer selected from the group consisting ofalkyl acrylates and methacrylates. At least one of the acid copolymercompositions is at least partially neutralized such that at least 70% ofall acid groups present in the composition are neutralized. At least oneof the acid copolymer compositions comprises a plasticizer in an amountof from 0.5 wt % to 80 wt %, based on the total weight of the acidcopolymer composition. In a particular aspect of this embodiment, theplasticizer is selected from fatty acid esters. In another particularaspect of this embodiment, the inner cover layer has a material hardnessless than the surface hardness of the outer core layer. In anotherparticular aspect of this embodiment, the modulus of the acid copolymerof the first acid copolymer composition is at least 10% less than themodulus of the acid copolymer of the second acid copolymer composition.In another particular aspect of this embodiment, the modulus of the acidcopolymer of second acid copolymer composition is at least 10% less thanthe modulus of the acid copolymer of the first acid copolymercomposition.

In another embodiment, the present invention is directed to a golf ballcomprising a core and a cover. The core has an overall diameter of from1.40 inches to 1.62 inches and consists of a center, an intermediatecore layer, and an outer core layer. The intermediate core layer has asurface hardness less than the surface hardness of the center and thesurface hardness of the outer core layer. One of the core layerscomprises a first acid copolymer composition and another of the corelayers comprises a second acid copolymer composition. The acid copolymercompositions comprise an acid copolymer of ethylene and anα,β-unsaturated carboxylic acid, optionally including a softeningmonomer selected from the group consisting of alkyl acrylates andmethacrylates. At least one of the acid copolymer compositions is atleast partially neutralized such that at least 70% of all acid groupspresent in the composition are neutralized. At least one of the acidcopolymer compositions comprises a plasticizer in an amount of from 0.5wt % to 80 wt %, based on the total weight of the acid copolymercomposition. In a particular aspect of this embodiment, the plasticizeris selected from fatty acid esters. In another particular aspect of thisembodiment, the center has a diameter of from 0.100 inches to 0.750inches and comprises the first acid copolymer composition, the outercore layer comprises the second acid copolymer composition, and thematerial hardness of the first acid copolymer composition is less thanthe material hardness of the second acid copolymer composition. Inanother particular aspect of this embodiment, the center has a diameterof from 0.125 inches to 0.750 inches and comprises the first acidcopolymer composition, the outer core layer comprises the second acidcopolymer composition, and the material hardness of the second acidcopolymer composition is less than the material hardness of the firstacid copolymer composition. In another particular aspect of thisembodiment, the center has a diameter of from 0.125 inches to 0.750inches and comprises the first acid copolymer composition, theintermediate core layer comprises the second acid copolymer composition,and the material hardness of the second acid copolymer composition isless than the material hardness of the first acid copolymer composition.In another particular aspect of this embodiment, the center has adiameter of from 0.125 inches to 0.750 inches, the intermediate corelayer comprises the first acid copolymer composition, the outer corelayer comprises the second acid copolymer composition, and the materialhardness of the first acid copolymer composition is less than thematerial hardness of the second acid copolymer composition.

In another embodiment, the present invention is directed to a golf ballconsisting essentially of a center, an outer core layer, an inner coverlayer, and an outer cover layer. The center has a diameter of from 0.50inches to 1.30 inches, a center hardness of 50 Shore C or greater, andis formed from a first acid copolymer composition comprising an acidcopolymer of ethylene and an α,β-unsaturated carboxylic acid, optionallyincluding a softening monomer selected from the group consisting ofalkyl acrylates and methacrylates. The outer core layer has a surfacehardness of 75 Shore C or greater and is formed from a second acidcopolymer composition comprising an acid copolymer of ethylene and anα,β-unsaturated carboxylic acid, optionally including a softeningmonomer selected from the group consisting of alkyl acrylates andmethacrylates. At least one of the acid copolymer compositions is atleast partially neutralized such that at least 70% of all acid groupspresent in the composition are neutralized. At least one of the acidcopolymer compositions comprises a plasticizer in an amount of from 0.5wt % to 80 wt %, based on the total weight of the acid copolymercomposition. In a particular aspect of this embodiment, the plasticizeris selected from fatty acid esters. In another particular aspect of thisembodiment, the inner cover layer has a material hardness less than thesurface hardness of the outer core layer. In another particular aspectof this embodiment, the modulus of the acid copolymer of the first acidcopolymer composition is at least 10% less than the modulus of the acidcopolymer of the second acid copolymer composition. In anotherparticular aspect of this embodiment, the modulus of the acid copolymerof second acid copolymer composition is at least 10% less than themodulus of the acid copolymer of the first acid copolymer composition.

DETAILED DESCRIPTION OF THE INVENTION

Golf balls of the present invention have at least two layers formed fromhighly neutralized acid polymer (“HNP”) compositions. In a particularembodiment, at least one of the HNP compositions is plasticized.Alternatively, at least one of the layers formed from an HNP compositionis replaced by a plasticized acid copolymer composition, wherein lessthan 80% of the acid groups of the acid copolymer are neutralized. Forpurposes of the present invention, a composition is “plasticized” if itcomprises from at least 0.5 wt %, based on the total weight of thecomposition, of a plasticizer, as disclosed herein.

In a particular embodiment, golf balls of the present invention have atleast one layer formed from a relatively soft, or relatively low modulusHNP composition, and at least one layer formed from a relatively hard,or relatively high modulus HNP composition. In a particular aspect ofthis embodiment, the relatively soft (or relatively low modulus) HNPcomposition and/or the relatively hard (or relatively high modulus) HNPcomposition comprises from 0.5 to 80 wt %, based on the total weight ofthe composition, of a plasticizer.

As used herein, “highly neutralized acid polymer” refers to an acidpolymer after at least 80%, preferably at least 90%, more preferably atleast 95%, and even more preferably 100%, of the acid groups of the acidpolymer are neutralized.

As used herein, “modulus” refers to flexural modulus as measured using astandard flex bar according to ASTM D790-B. For purposes of the presentdisclosure, material hardness is measured according to ASTM D2240 andgenerally involves measuring the hardness of a flat “slab” or “button”formed of the material. It should be understood that there is afundamental difference between “material hardness” and “hardness asmeasured directly on a golf ball.” Hardness as measured directly on agolf ball (or other spherical surface) typically results in a differenthardness value than material hardness. This difference in hardnessvalues is due to several factors including, but not limited to, ballconstruction (i.e., core type, number of core and/or cover layers,etc.), ball (or sphere) diameter, and the material composition ofadjacent layers. It should also be understood that the two measurementtechniques are not linearly related and, therefore, one hardness valuecannot easily be correlated to the other. Unless stated otherwise, thehardness values given herein for cover materials are material hardnessvalues measured according to ASTM D2240, with all values reportedfollowing 10 days of aging at 50% relative humidity and 23° C.

The surface hardness of a golf ball layer is obtained from the averageof a number of measurements taken from opposing hemispheres of a core,taking care to avoid making measurements on the parting line of the coreor on surface defects, such as holes or protrusions. Hardnessmeasurements are made pursuant to ASTM D-2240 “Indentation Hardness ofRubber and Plastic by Means of a Durometer.” Because of the curvedsurface of a core, care must be taken to insure that the golf ball orgolf ball subassembly is centered under the durometer indentor before asurface hardness reading is obtained. A calibrated, digital durometer,capable of reading to 0.1 hardness units is used for all hardnessmeasurements and is set to take hardness readings at 1 second after themaximum reading is obtained. The digital durometer must be attached to,and its foot made parallel to, the base of an automatic stand, such thatthe weight on the durometer and attack rate conform to ASTM D-2240.

The center hardness of a core is obtained according to the followingprocedure. The core is gently pressed into a hemispherical holder havingan internal diameter approximately slightly smaller than the diameter ofthe core, such that the core is held in place in the hemisphericalportion of the holder while concurrently leaving the geometric centralplane of the core exposed. The core is secured in the holder byfriction, such that it will not move during the cutting and grindingsteps, but the friction is not so excessive that distortion of thenatural shape of the core would result. The core is secured such thatthe parting line of the core is roughly parallel to the top of theholder. The diameter of the core is measured 90 degrees to thisorientation prior to securing. A measurement is also made from thebottom of the holder to the top of the core to provide a reference pointfor future calculations. A rough cut, made slightly above the exposedgeometric center of the core using a band saw or other appropriatecutting tool, making sure that the core does not move in the holderduring this step. The remainder of the core, still in the holder, issecured to the base plate of a surface grinding machine. The exposed‘rough’ surface is ground to a smooth, flat surface, revealing thegeometric center of the core, which can be verified by measuring theheight of the bottom of the holder to the exposed surface of the core,making sure that exactly half of the original height of the core, asmeasured above, has been removed to within ±0.004 inches. Leaving thecore in the holder, the center of the core is found with a center squareand carefully marked and the hardness is measured at the center mark.

Golf ball core layers of the present invention may have a zero ornegative or positive hardness gradient. A hardness gradient is definedby hardness measurements made at the surface of the layer (e.g., center,outer core layer, etc.) and radially inward towards the center of theball, typically at 2 mm increments. For purposes of the presentinvention, “negative” and “positive” refer to the result of subtractingthe hardness value at the innermost portion of the golf ball componentfrom the hardness value at the outer surface of the component. Forexample, if the outer surface of a solid core has a lower hardness valuethan the center (i.e., the surface is softer than the center), thehardness gradient will be deemed a “negative” gradient. In measuring thehardness gradient of a core, the center hardness is first determinedaccording to the procedure above for obtaining the center hardness of acore. Once the center of the core is marked and the hardness thereof isdetermined, hardness measurements at any distance from the center of thecore may be measured by drawing a line radially outward from the centermark, and measuring and marking the distance from the center, typicallyin 2 mm increments. All hardness measurements performed on a planepassing through the geometric center are performed while the core isstill in the holder and without having disturbed its orientation, suchthat the test surface is constantly parallel to the bottom of theholder. The hardness difference from any predetermined location on thecore is calculated as the average surface hardness minus the hardness atthe appropriate reference point, e.g., at the center of the core for asingle, solid core, such that a core surface softer than its center willhave a negative hardness gradient. Hardness gradients are disclosed morefully, for example, in U.S. patent application Ser. No. 11/832,163,filed on Aug. 1, 2007; Ser. No. 11/939,632, filed on Nov. 14, 2007; Ser.No. 11/939,634, filed on Nov. 14, 2007; Ser. No. 11/939,635, filed onNov. 14, 2007; and Ser. No. 11/939,637, filed on Nov. 14, 2007; theentire disclosure of each of these references is hereby incorporatedherein by reference.

Relatively Soft/Low Modulus HNP Composition

Relatively soft HNP compositions of the present invention have amaterial hardness of 80 Shore D or less, and preferably have a Shore Dhardness of 55 or less or a Shore D hardness within the range having alower limit of 10 or 20 or 30 or 37 or 39 or 40 or 45 and an upper limitof 48 or 50 or 52 or 55 or 60 or 80. Alternatively, soft HNPcompositions of the present invention have a material hardness within arange having a lower limit of 30 or 40 or 45 Shore C and an upper limitof 55 or 60 or 80 Shore C.

Low modulus HNP compositions of the present invention comprise at leastone low modulus HNP having a modulus within a range having a lower limitof 1,000 or 5,000 or 10,000 psi and an upper limit of 17,000 or 25,000or 28,000 or 30,000 or 35,000 or 45,000 or 50,000 or 55,000 psi. In apreferred embodiment, the modulus of the low modulus HNP is at least 10%less, or at least 20% less, or at least 25% less, or at least 30% less,or at least 35% less, than the modulus of the high modulus HNP.

Relatively soft HNP compositions of the present invention comprise atleast one highly neutralized acid polymer. In a preferred embodiment,the highly neutralized acid polymer of the relatively soft HNPcomposition is a low modulus HNP having a modulus within a range havinga lower limit of 1,000 or 5,000 or 10,000 psi and an upper limit of17,000 or 25,000 or 28,000 or 30,000 or 35,000 or 45,000 or 50,000 or55,000 psi. In a particular aspect of this embodiment, the modulus ofthe low modulus HNP is at least 10% less, or at least 20% less, or atleast 25% less, or at least 30% less, or at least 35% less, than that ofthe high modulus HNP discussed below.

HNPs of the relatively soft/low modulus HNP compositions of the presentinvention are salts of acid copolymers. It is understood that the HNPmay be a blend of two or more HNPs. The acid copolymer of the HNP is anO/X/Y-type copolymer, wherein O is an α-olefin, X is a C₃-C₈α,β-ethylenically unsaturated carboxylic acid, and Y is a softeningmonomer. O is preferably ethylene. X is preferably selected from (meth)acrylic acid, ethacrylic acid, maleic acid, crotonic acid, fumaric acid,and itaconic acid. (Meth) acrylic acid is particularly preferred. Asused herein, “(meth) acrylic acid” means methacrylic acid and/or acrylicacid. Likewise, “(meth) acrylate” means methacrylate and/or acrylate. Yis preferably an alkyl (meth) acrylate, wherein the alkyl groups havefrom 1 to 8 carbon atoms. Preferred O/X/Y-type copolymers are thosewherein O is ethylene, X is (meth) acrylic acid, and Y is selected from(meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate,methyl (meth) acrylate, and ethyl (meth) acrylate. Particularlypreferred O/X/Y-type copolymers are ethylene/(meth) acrylic acid/n-butylacrylate, ethylene/(meth) acrylic acid/methyl acrylate, andethylene/(meth) acrylic acid/ethyl acrylate.

The acid copolymer of the HNP typically includes the α-olefin in anamount of at least 15 wt %, or at least 25 wt %, or at least 40 wt %, orat least 60 wt %, based on the total weight of the acid copolymer. Theamount of C₃-C₈ α,β-ethylenically unsaturated carboxylic acid in theacid copolymer is typically within a range having a lower limit of 1 or2 or 4 or 6 or 8 or 10 or 12 or 15 or 16 or 20 wt % and an upper limitof 20 or 25 or 26 or 30 or 35 or 40 wt %, based on the total weight ofthe acid copolymer. The amount of optional softening monomer in the acidcopolymer is typically within a range having a lower limit of 0 or 1 or3 or 5 or 11 or 15 or 20 wt % and an upper limit of 23 or 25 or 30 or 35or 50 wt %, based on the total weight of the acid copolymer.

Particularly suitable acid copolymers of the HNP of the relativelysoft/low modulus HNP composition include very low modulus ionomer-(“VLMI-”) type ethylene-acid polymers, such as Surlyn® 6320, Surlyn®8120, Surlyn® 8320, and Surlyn® 9320. Surlyn® ionomers are commerciallyavailable from E. I. du Pont de Nemours and Company. Also suitable areDuPont® HPF 1000, HPF 2000, HPF AD 1035, HPF AD 1040, ionomericmaterials commercially available from E. I. du Pont de Nemours andCompany.

Additional suitable acid copolymers are disclosed, for example, in U.S.Patent Application Publication Nos. 2005/0148725, 2005/0020741,2004/0220343, and 2003/0130434, and U.S. Pat. Nos. 5,691,418, 6,562,906,6,653,382, 6,777,472, 6,762,246, and 6,815,480, the entire disclosuresof which are hereby incorporated herein by reference.

In a preferred embodiment, the HNP of the relatively soft/low modulusHNP composition is formed by reacting an acid copolymer, which isoptionally partially neutralized, with a sufficient amount of cationsource, in the presence of a high molecular weight organic acid or saltthereof, such that at least 80%, preferably at least 90%, morepreferably at least 95%, and even more preferably 100%, of all acidgroups present are neutralized. In a particular embodiment, the cationsource is present in an amount sufficient to neutralize, theoretically,greater than 100%, or 105% or greater, or 110% or greater, or 115% orgreater, or 120% or greater, or 125% or greater, or 200% or greater, or250% or greater of all acid groups present in the composition. The acidcopolymer can be reacted with the high molecular weight organic acid orsalt thereof and the cation source simultaneously, or the acid copolymercan be reacted with the high molecular weight organic acid prior to theaddition of the cation source.

Suitable high molecular weight organic acids are aliphatic organicacids, aromatic organic acids, saturated monofunctional organic acids,unsaturated monofunctional organic acids, multi-unsaturatedmonofunctional organic acids, and dimerized derivatives thereof.Particular examples of suitable organic acids include, but are notlimited to, caproic acid, caprylic acid, capric acid, lauric acid,stearic acid, behenic acid, erucic acid, oleic acid, linoleic acid,myristic acid, benzoic acid, palmitic acid, phenylacetic acid,naphthalenoic acid, dimerized derivatives thereof, and combinationsthereof. Salts of high molecular weight organic acids comprise thesalts, particularly the barium, lithium, sodium, zinc, bismuth,chromium, cobalt, copper, potassium, stontium, titanium, tungsten,magnesium, and calcium salts, of aliphatic organic acids, aromaticorganic acids, saturated monofunctional organic acids, unsaturatedmonofunctional organic acids, multi-unsaturated monofunctional organicacids, dimerized derivatives thereof, and combinations thereof. Suitableorganic acids and salts thereof are more fully described, for example,in U.S. Pat. No. 6,756,436, the entire disclosure of which is herebyincorporated herein by reference.

Suitable cation sources include metal ions and compounds of alkalimetals, alkaline earth metals, and transition metals; metal ions andcompounds of rare earth elements; silicone, silane, and silicatederivatives and complex ligands; and combinations thereof. Preferredcation sources are metal ions and compounds of magnesium, sodium,potassium, cesium, calcium, barium, manganese, copper, zinc, tin,lithium, and rare earth metals. The acid copolymer may be at leastpartially neutralized prior to contacting the acid copolymer with thecation source to form the HNP. Methods of preparing ionomers are wellknown, and are disclosed, for example, in U.S. Pat. No. 3,264,272, theentire disclosure of which is hereby incorporated herein by reference.The acid copolymer can be a direct copolymer wherein the polymer ispolymerized by adding all monomers simultaneously, as disclosed, forexample, in U.S. Pat. No. 4,351,931, the entire disclosure of which ishereby incorporated herein by reference. Alternatively, the acidcopolymer can be a graft copolymer wherein a monomer is grafted onto anexisting polymer, as disclosed, for example, in U.S. Patent ApplicationPublication No. 2002/0013413, the entire disclosure of which is herebyincorporated herein by reference.

Relatively soft/low modulus HNP compositions of the present inventionoptionally contain one or more melt flow modifiers. The amount of meltflow modifier in the composition is readily determined such that themelt flow index of the composition is at least 0.1 g/10 min, preferablyfrom 0.5 g/10 min to 10.0 g/10 min, and more preferably from 1.0 g/10min to 6.0 g/10 min, as measured using ASTM D-1238, condition E, at 190°C., using a 2160 gram weight.

Suitable melt flow modifiers include, but are not limited to, highmolecular weight organic acids and salts thereof, polyamides,polyesters, polyacrylates, polyurethanes, polyethers, polyureas,polyhydric alcohols, and combinations thereof. Suitable organic acidsare aliphatic organic acids, aromatic organic acids, saturatedmono-functional organic acids, unsaturated monofunctional organic acids,multi-unsaturated mono-functional organic acids, and dimerizedderivatives thereof. Particular examples of suitable organic acidsinclude, but are not limited to, caproic acid, caprylic acid, capricacid, lauric acid, stearic acid, behenic acid, erucic acid, oleic acid,linoleic acid, myristic acid, benzoic acid, palmitic acid, phenylaceticacid, naphthalenoic acid, dimerized derivatives thereof. Suitableorganic acids are more fully described, for example, in U.S. Pat. No.6,756,436, the entire disclosure of which is hereby incorporated hereinby reference. In a particular embodiment, the HNP composition comprisesan organic acid salt in an amount of 20 phr or greater, or 25 phr orgreater, or 30 phr or greater, or 35 phr or greater, or 40 phr orgreater.

Additional melt flow modifiers suitable for use in compositions of thepresent invention, include the non-fatty acid melt flow modifiersdescribed in copending U.S. patent application Ser. Nos. 11/216,725 and11/216,726, the entire disclosures of which are hereby incorporatedherein by reference.

Relatively soft/low modulus HNP compositions of the present inventionoptionally include additive(s) and/or filler(s) in an amount of 50 wt %or less, or 30 wt % or less, or 15 wt % or less, based on the totalweight of the relatively soft/low modulus HNP composition. Suitableadditives and fillers include, but are not limited to, chemical blowingand foaming agents, optical brighteners, coloring agents, fluorescentagents, whitening agents, UV absorbers, light stabilizers, defoamingagents, processing aids, mica, talc, nano-fillers, antioxidants,stabilizers, softening agents, fragrance components, plasticizers,impact modifiers, TiO₂, acid copolymer wax, surfactants, and fillers,such as zinc oxide, tin oxide, barium sulfate, zinc sulfate, calciumoxide, calcium carbonate, zinc carbonate, barium carbonate, clay,tungsten, tungsten carbide, silica, lead silicate, regrind (recycledmaterial), and mixtures thereof. Suitable additives are more fullydescribed in, for example, U.S. Patent Application Publication No.2003/0225197, the entire disclosure of which is hereby incorporatedherein by reference.

Relatively soft/low modulus HNP compositions of the present inventionoptionally contain a high modulus HNP.

In a particular embodiment, the relatively soft/low modulus HNPcomposition has a moisture vapor transmission rate of 8 g-mil/100in²/day or less (i.e., 3.2 g-mm/m²·day or less), or 5 g-mil/100 in²/dayor less (i.e., 2.0 g-mm/m²·day or less), or 3 g-mil/100 in²/day or less(i.e., 1.2 g-mm/m²·day or less), or 2 g-mil/100 in²/day or less (i.e.,0.8 g-mm/m² day or less), or 1 g-mil/100 in²/day or less (i.e., 0.4g-mm/m² day or less), or less than 1 g-mil/100 in²/day (i.e., less than0.4 g-mm/m² day). As used herein, moisture vapor transmission rate(“MVTR”) is given in g-mil/100 in²/day, and is measured at 20° C. andaccording to ASTM F1249-99. In a preferred aspect of this embodiment,the relatively soft/low modulus HNP composition comprises a low modulusHNP prepared using a cation source which is less hydrophilic thanconventional magnesium-based cation sources. Suitable moisture resistantHNP compositions are disclosed, for example, in U.S. Patent ApplicationPublication Nos. 2005/0267240, 2006/0106175 and 2006/0293464, the entiredisclosures of which are hereby incorporated herein by reference.

In another particular embodiment, a sphere formed from the relativelysoft/low modulus HNP composition has a compression of 80 or less, or 70or less, or 65 or less, or 60 or less, or 50 or less, or 40 or less, or30 or less, or 20 or less.

Relatively soft/low modulus HNP compositions of the present inventionare not limited by any particular method or any particular equipment formaking the compositions. In a preferred embodiment, the composition isprepared by the following process. The acid polymer(s), preferably aVLMI-type ethylene-acid terpolymer, high molecular weight organicacid(s) or salt(s) thereof, and optionally additive(s)/filler(s) aresimultaneously or individually fed into a melt extruder, such as asingle or twin screw extruder. A suitable amount of cation source issimultaneously or subsequently added such that at least 80%, preferablyat least 90%, more preferably at least 95%, and even more preferably atleast 100%, of all acid groups present are neutralized. Optionally, thecation source is added in an amount sufficient to neutralize,theoretically, 105% or greater, or 110% or greater, or 115% or greater,or 120% or greater, or 125% or greater, or 200% or greater, or 250% orgreater of all acid groups present in the composition. The acid polymermay be at least partially neutralized prior to the above process. Thecomponents are intensively mixed prior to being extruded as a strandfrom the die-head.

Relatively soft/low modulus HNP compositions of the present inventionoptionally comprise one or more additional polymers, such as partiallyneutralized ionomers (e.g., as disclosed in U.S. Patent ApplicationPublication No. 2006/0128904, the entire disclosure of which is herebyincorporated herein by reference); bimodal ionomers (e.g., as disclosedin U.S. Patent Application Publication No. 2004/0220343 and U.S. Pat.Nos. 6,562,906, 6,762,246, 7,273,903, 8,193,283, 8,410,219, and8,410,220, the entire disclosures of which are hereby incorporatedherein by reference, and particularly Surlyn® AD 1043, 1092, and 1022ionomer resins, commercially available from E. I. du Pont de Nemours andCompany); ionomers modified with rosins (e.g., as disclosed in U.S.Patent Application Publication No. 2005/0020741, the entire disclosureof which is hereby incorporated by reference); soft and resilientethylene copolymers (e.g., as disclosed U.S. Patent ApplicationPublication No. 2003/0114565, the entire disclosure of which is herebyincorporated herein by reference); polyolefins; polyamides; polyesters;polyethers; polycarbonates; polysulfones; polyacetals; polylactones;acrylonitrile-butadiene-styrene resins; polyphenylene oxide;polyphenylene sulfide; styrene-acrylonitrile resins; styrene maleicanhydride; polyimides; aromatic polyketones; ionomers and ionomericprecursors, acid copolymers, and conventional HNPs; polyurethanes;grafted and non-grafted metallocene-catalyzed polymers; single-sitecatalyst polymerized polymers; high crystalline acid polymers; cationicionomers; natural and synthetic rubbers, including, but not limited to,ethylene propylene rubber (“EPR”), ethylene propylene diene rubber(“EPDM”), styrenic block copolymer rubbers (such as SI, SIS, SB, SBS,SIBS, and the like, where “S” is styrene, “I” is isobutylene, and “B” isbutadiene), butyl rubber, halobutyl rubber, copolymers of isobutyleneand para-alkylstyrene, halogenated copolymers of isobutylene andpara-alkylstyrene, natural rubber, polyisoprene, copolymers of butadienewith acrylonitrile, polychloroprene, alkyl acrylate rubber (such asethylene-alkyl acrylates and ethylene-alkyl methacrylates, and, morespecifically, ethylene-ethyl acrylate, ethylene-methyl acrylate, andethylene-butyl acrylate), chlorinated isoprene rubber, acrylonitrilechlorinated isoprene rubber, and polybutadiene rubber (cis and trans);and combinations thereof. Particular polyolefins suitable for blendinginclude one or more, linear, branched, or cyclic, C₂-C₄₀ olefins,particularly polymers comprising ethylene or propylene copolymerizedwith one or more C₂-C₄₀ olefins, C₃-C₂₀ α-olefins, or C₃-C₁₀ α-olefins.Particular conventional HNPs suitable for blending include, but are notlimited to, one or more of the HNPs disclosed in U.S. Pat. Nos.6,756,436, 6,894,098, and 6,953,820, the entire disclosures of which arehereby incorporated herein by reference. Additional suitable blendpolymers include those described in U.S. Pat. No. 5,981,658, for exampleat column 14, lines 30 to 56, the entire disclosure of which is herebyincorporated herein by reference. The blends described herein may beproduced by post-reactor blending, by connecting reactors in series tomake reactor blends, or by using more than one catalyst in the samereactor to produce multiple species of polymer. The polymers may bemixed prior to being put into an extruder, or they may be mixed in anextruder. In a particular embodiment, the HNP composition comprises anacid copolymer and an additional polymer component, wherein theadditional polymer component is a non-acid polymer present in an amountof greater than 50 wt %, or an amount within a range having a lowerlimit of 50 or 55 or 60 or 65 or 70 and an upper limit of 80 or 85 or90, based on the combined weight of the acid copolymer and the non-acidpolymer. In another particular embodiment, the HNP composition comprisesan acid copolymer and an additional polymer component, wherein theadditional polymer component is a non-acid polymer present in an amountof less than 50 wt %, or an amount within a range having a lower limitof 10 or 15 or 20 or 25 or 30 and an upper limit of 40 or 45 or 50,based on the combined weight of the acid copolymer and the non-acidpolymer.

Particularly suitable relatively soft/low modulus HNP compositionsinclude, but are not limited to, the highly-resilient thermoplasticcompositions disclosed in U.S. Patent Application Publication No.2005/0148725; the highly-neutralized ethylene copolymers disclosed inU.S. Pat. Nos. 6,653,382 and 6,777,472, and U.S. Patent ApplicationPublication No. 2003/0130434; and the highly-resilient thermoplasticelastomer compositions disclosed in U.S. Pat. No. 6,815,480; the entiredisclosures of which are hereby incorporated herein by reference.

In a particular embodiment, the relatively soft/low modulus HNPcomposition is formed by blending an acid polymer, a non-acid polymer, acation source, and a fatty acid or metal salt thereof. For purposes ofthe present invention, maleic anhydride modified polymers are definedherein as a non-acid polymer despite having anhydride groups that canring-open to the acid form during processing of the polymer to form theHNP compositions herein. The maleic anhydride groups are grafted onto apolymer, are present at relatively very low levels, and are not part ofthe polymer backbone, as is the case with the acid polymers, which areexclusively E/X and E/X/Y copolymers of ethylene and an acid,particularly methacrylic acid and acrylic acid.

In a particular aspect of this embodiment, the acid polymer is selectedfrom ethylene-acrylic acid and ethylene-methacrylic acid copolymers,optionally containing a softening monomer selected from n-butyl acrylateand iso-butyl acrylate. Examples of particularly suitable commerciallyavailable acid polymers include, but are not limited to, those given inTable 1 below.

TABLE 1 Melt Index Softening (2.16 kg, Acid Monomer 190° C., AcidPolymer (wt %) (wt %) g/10 min) Nucrel ® 9-1 methacrylic acid n-butylacrylate 25 (9.0) (23.5) Nucrel ® 599 methacrylic acid none 450 (10.0)Nucrel ® 960 methyacrylic acid none 60 (15.0) Nucrel ® 0407 methacrylicacid none 7.5 (4.0) Nucrel ® 0609 methacrylic acid none 9 (6.0) Nucrel ®1214 methacrylic acid none 13.5 (12.0) Nucrel ® 2906 methacrylic acidnone 60 (19.0) Nucrel ® 2940 methacrylic acid none 395 (19.0) Nucrel ®30707 acrylic acid none 7 (7.0) Nucrel ® 31001 acrylic acid none 1.3(9.5) Nucrel ® AE methacrylic acid isobutyl acrylate 11 (2.0) (6.0)Nucrel ® 2806 acrylic acid none 60 (18.0) Nucrel ® 0403 methacrylic acidnone 3 (4.0) Nucrel ® 925 methacrylic acid none 25 (15.0) Escor ® AT-310acrylic acid methyl acrylate 6 (6.5) (6.5) Escor ® AT-325 acrylic acidmethyl acrylate 20 (6.0) (20.0) Escor ® AT-320 acrylic acid methylacrylate 5 (6.0) (18.0) Escor ® 5070 acrylic acid none 30 (9.0) Escor ®5100 acrylic acid none 8.5 (11.0) Escor ® 5200 acrylic acid none 38(15.0) A-C ® 5120 acrylic acid none not reported (15) A-C ® 540 acrylicacid none not reported (5) A-C ® 580 acrylic acid none not reported (10)Primacor ® 3150 acrylic acid none 5.8 (6.5) Primacor ® 3330 acrylic acidnone 11 (3.0) Primacor ® 5985 acrylic acid none 240 (20.5) Primacor ®5986 acrylic acid none 300 (20.5) Primacor ® 5980I acrylic acid none 300(20.5) Primacor ® 5990I acrylic acid none 1300 (20.0) XUS 60751.17acrylic acid none 600 (19.8) XUS 60753.02L acrylic acid none 60 (17.0)

Nucrel® acid polymers are commercially available from E. I. du Pont deNemours and Company.

Escort acid polymers are commercially available from ExxonMobil ChemicalCompany.

A-C® acid polymers are commercially available from HoneywellInternational Inc.

Primacor® acid polymers and XUS acid polymers are commercially availablefrom The Dow Chemical Company.

In another particular aspect of this embodiment, the non-acid polymer isan elastomeric polymer. Suitable elastomeric polymers include, but arenot limited to:

-   -   (a) ethylene-alkyl acrylate polymers, particularly        polyethylene-butyl acrylate, polyethylene-methyl acrylate, and        polyethylene-ethyl acrylate;    -   (b) metallocene-catalyzed polymers;    -   (c) ethylene-butyl acrylate-carbon monoxide polymers and        ethylene-vinyl acetate-carbon monoxide polymers;    -   (d) polyethylene-vinyl acetates;    -   (e) ethylene-alkyl acrylate polymers containing a cure site        monomer;    -   (f) ethylene-propylene rubbers and ethylene-propylene-diene        monomer rubbers;    -   (g) olefinic ethylene elastomers, particularly ethylene-octene        polymers, ethylene-butene polymers, ethylene-propylene polymers,        and ethylene-hexene polymers;    -   (h) styrenic block copolymers;    -   (i) polyester elastomers;    -   (j) polyamide elastomers;    -   (k) polyolefin rubbers, particularly polybutadiene,        polyisoprene, and styrene-butadiene rubber; and    -   (l) thermoplastic polyurethanes.

Examples of particularly suitable commercially available non-acidpolymers include, but are not limited to, Lotader® ethylene-alkylacrylate polymers and Lotryl® ethylene-alkyl acrylate polymers, andparticularly Lotader® 4210, 4603, 4700, 4720, 6200, 8200, and AX8900commercially available from Arkema Corporation; Elvaloy® ACethylene-alkyl acrylate polymers, and particularly AC 1224, AC 1335, AC2116, AC3117, AC3427, and AC34035, commercially available from E. I. duPont de Nemours and Company; Fusabond® elastomeric polymers, such asethylene vinyl acetates, polyethylenes, metallocene-catalyzedpolyethylenes, ethylene propylene rubbers, and polypropylenes, andparticularly Fusabond N525, C190, C250, A560, N416, N493, N614, P614,M603, E100, E158, E226, E265, E528, and E589, commercially availablefrom E. I. du Pont de Nemours and Company; Honeywell A-C polyethylenesand ethylene maleic anhydride copolymers, and particularly A-C 5180, A-C575, A-C 573, A-C 655, and A-C 395, commercially available fromHoneywell; Nordel® IP rubber, Elite® polyethylenes, Engage® elastomers,and Amplify® functional polymers, and particularly Amplify® GR 207, GR208, GR 209, GR 213, GR 216, GR 320, GR 380, and EA 100, commerciallyavailable from The Dow Chemical Company; Enable® metallocenepolyethylenes, Exact® plastomers, Vistamaxx® propylene-based elastomers,and Vistalon® EPDM rubber, commercially available from ExxonMobilChemical Company; Starflex® metallocene linear low density polyethylene,commercially available from LyondellBasell; Elvaloy® HP4051, HP441,HP661 and HP662 ethylene-butyl acrylate-carbon monoxide polymers andElvaloy® 741, 742 and 4924 ethylene-vinyl acetate-carbon monoxidepolymers, commercially available from E. I. du Pont de Nemours andCompany; Evatane® ethylene-vinyl acetate polymers having a vinyl acetatecontent of from 18 to 42%, commercially available from ArkemaCorporation; Elvax® ethylene-vinyl acetate polymers having a vinylacetate content of from 7.5 to 40%, commercially available from E. I. duPont de Nemours and Company; Vamac® G terpolymer of ethylene,methylacrylate and a cure site monomer, commercially available from E.I. du Pont de Nemours and Company; Vistalon® EPDM rubbers, commerciallyavailable from ExxonMobil Chemical Company; Kraton® styrenic blockcopolymers, and particularly Kraton® FG1901GT, FG1924GT, and RP6670GT,commercially available from Kraton Performance Polymers Inc.; Septon®styrenic block copolymers, commercially available from Kuraray Co.,Ltd.; Hytrel® polyester elastomers, and particularly Hytrel® 3078, 4069,and 556, commercially available from E. I. du Pont de Nemours andCompany; Riteflex® polyester elastomers, commercially available fromCelanese Corporation; Pebax® thermoplastic polyether block amides, andparticularly Pebax® 2533, 3533, 4033, and 5533, commercially availablefrom Arkema Inc.; Affinity® and Affinity® GA elastomers, Versify®ethylene-propylene copolymer elastomers, and Infuse® olefin blockcopolymers, commercially available from The Dow Chemical Company;Exxelor® polymer resins, and particularly Exxelor® PE 1040, PO 1015, PO1020, VA 1202, VA 1801, VA 1803, and VA 1840, commercially availablefrom ExxonMobil Chemical Company; and Royaltuf® EPDM, and particularlyRoyaltuf®498 maleic anhydride modified polyolefin based on an amorphousEPDM and Royaltuf®485 maleic anhydride modified polyolefin based on ansemi-crystalline EPDM, commercially available from Chemtura Corporation.

Additional examples of particularly suitable commercially availableelastomeric polymers include, but are not limited to, those given inTable 2 below.

TABLE 2 Melt Index % Maleic (2.16 kg, 190° C., % Ester Anhydride g/10min) Polyethylene Butyl Acrylates Lotader ® 3210 6 3.1 5 Lotader ® 42106.5 3.6 9 Lotader ® 3410 17 3.1 5 Lotryl ® 17BA04 16-19 0 3.5-4.5Lotryl ® 35BA320 33-37 0 260-350 Elvaloy ® AC 3117 17 0 1.5 Elvaloy ® AC3427 27 0 4 Elvaloy ® AC 34035 35 0 40 Polyethylene Methyl AcrylatesLotader ® 4503 19 0.3 8 Lotader ® 4603 26 0.3 8 Lotader ® AX 8900 26 8%GMA 6 Lotryl ® 24MA02 23-26 0 1-3 Elvaloy ® AC 12024S 24 0 20 Elvaloy ®AC 1330 30 0 3 Elvaloy ® AC 1335 35 0 3 Elvaloy ® AC 1224 24 0 2Polyethylene Ethyl Acrylates Lotader ® 6200 6.5 2.8 40 Lotader ® 82006.5 2.8 200 Lotader ® LX 4110 5 3.0 5 Lotader ® HX 8290 17 2.8 70Lotader ® 5500 20 2.8 20 Lotader ® 4700 29 1.3 7 Lotader ® 4720 29 0.3 7Elvaloy ® AC 2116 16 0 1

The acid polymer and non-acid polymer are combined and reacted with acation source, such that at least 80% of all acid groups present areneutralized. The present invention is not meant to be limited by aparticular order for combining and reacting the acid polymer, non-acidpolymer and cation source. In a particular embodiment, the fatty acid ormetal salt thereof is used in an amount such that the fatty acid ormetal salt thereof is present in the HNP composition in an amount offrom 10 wt % to 60 wt %, or within a range having a lower limit of 10 or20 or 30 or 40 wt % and an upper limit of 40 or 50 or 60 wt %, based onthe total weight of the HNP composition. Suitable cation sources andfatty acids and metal salts thereof are further disclosed above.

In another particular aspect of this embodiment, the acid polymer is anethylene-acrylic acid polymer having an acid content of 19 wt % orgreater, the non-acid polymer is a metallocene-catalyzed ethylene-butenecopolymer, optionally modified with maleic anhydride, the cation sourceis magnesium, and the fatty acid or metal salt thereof is magnesiumoleate present in the composition in an amount of 20 to 50 wt %, basedon the total weight of the composition.

The relatively soft/low modulus HNP composition optionally comprisesfrom 0.5 wt % to 80 wt % of a plasticizer, based on the total weight ofthe composition. Suitable plasticizers are disclosed further below.

Relatively Hard/High Modulus HNP Composition

Relatively hard HNP compositions of the present invention have a Shore Dhardness of 35 or greater, and preferably have a Shore D hardness of 45or greater or a Shore D hardness with the range having a lower limit of45 or 50 or 55 or 57 or 58 or 60 or 65 or 70 or 75 and an upper limit of80 or 85 or 90 or 95. Alternatively, hard HNP compositions of thepresent invention have a material hardness within a range having a lowerlimit of 65 or 70 or 75 Shore C and an upper limit of 85 or 90 or 95Shore C.

High modulus HNP compositions of the present invention comprise at leastone high modulus HNP having a modulus within a range having a lowerlimit of 25,000 or 27,000 or 30,000 or 40,000 or 45,000 or 50,000 or55,000 or 60,000 psi and an upper limit of 72,000 or 75,000 or 100,000or 150,000 psi.

Relatively hard HNP compositions of the present invention comprise atleast one highly neutralized acid polymer. In a preferred embodiment,the highly neutralized acid polymer of the relatively hard HNPcomposition is a high modulus HNP having a modulus within a range havinga lower limit of 25,000 or 27,000 or 30,000 or 40,000 or 45,000 or50,000 or 55,000 or 60,000 psi and an upper limit of 72,000 or 75,000 or100,000 or 150,000 psi.

HNPs of the relatively hard/high modulus HNP compositions of the presentinvention are salts of acid copolymers. It is understood that the HNPmay be a blend of two or more HNPs. Preferred acid copolymers arecopolymers of an α-olefin and a C₃-C₈ α,β-ethylenically unsaturatedcarboxylic acid. The acid is typically present in the acid copolymer inan amount within a range having a lower limit of 1 or 2 or 4 or 6 or 8or 10 or 12 or 15 or 16 or 20 wt % and an upper limit of 20 or 25 or 26or 30 or 35 or 40 wt %, based on the total weight of the acid copolymer.The α-olefin is preferably selected from ethylene and propylene. Theacid is preferably selected from (meth) acrylic acid, ethacrylic acid,maleic acid, crotonic acid, fumaric acid, and itaconic acid. (Meth)acrylic acid is particularly preferred. In a preferred embodiment, theHNP of the relatively hard HNP composition has a higher level of acidthan the HNP of the relatively soft HNP composition.

Suitable acid copolymers include partially neutralized acid polymers.Examples of suitable partially neutralized acid polymers include, butare not limited to, Surlyn® ionomers, commercially available from E. I.du Pont de Nemours and Company; AClyn® ionomers, commercially availablefrom Honeywell International Inc.; and Iotek® ionomers, commerciallyavailable from ExxonMobil Chemical Company. Also suitable are DuPont®HPF 1000, HPF 2000, HPF AD 1035, HPF AD 1040, ionomeric materialscommercially available from E. I. du Pont de Nemours and Company.Additional suitable acid polymers are more fully described, for example,in U.S. Pat. Nos. 6,562,906, 6,762,246, and 6,953,820 and U.S. PatentApplication Publication Nos. 2005/0049367, 2005/0020741, and2004/0220343, the entire disclosures of which are hereby incorporatedherein by reference.

In a preferred embodiment, the HNP of the relatively hard/high modulusHNP composition is formed by reacting an acid copolymer, which mayalready be partially neutralized, with a sufficient amount of cationsource, optionally in the presence of a high molecular weight organicacid or salt thereof, such that at least 80%, preferably at least 90%,more preferably at least 95%, and even more preferably 100%, of all acidgroups present are neutralized. In a particular embodiment, the cationsource is present in an amount sufficient to neutralize, theoretically,greater than 100%, or 105% or greater, or 110% or greater, or 115% orgreater, or 120% or greater, or 125% or greater, or 200% or greater, or250% or greater of all acid groups present in the composition. Suitablecation sources include metal ions and compounds of alkali metals,alkaline earth metals, and transition metals; metal ions and compoundsof rare earth elements; silicone, silane, and silicate derivatives andcomplex ligands; and combinations thereof. Preferred cation sources aremetal ions and compounds of magnesium, sodium, potassium, cesium,calcium, barium, manganese, copper, zinc, tin, lithium, and rare earthmetals. Metal ions and compounds of calcium and magnesium areparticularly preferred. The acid copolymer may be at least partiallyneutralized prior to contacting the acid copolymer with the cationsource to form the HNP. As previously stated, methods of preparingionomers, and the acid copolymers on which ionomers are based, aredisclosed, for example, in U.S. Pat. Nos. 3,264,272, and 4,351,931, andU.S. Patent Application Publication No. 2002/0013413.

Relatively hard/high modulus HNP compositions of the present inventionoptionally contain one or more melt flow modifiers. The amount of meltflow modifier in the composition is readily determined such that themelt flow index of the composition is at least 0.1 g/10 min, preferablyfrom 0.5 g/10 min to 10.0 g/10 min, and more preferably from 1.0 g/10min to 6.0 g/10 min, as measured using ASTM D-1238, condition E, at 190°C., using a 2160 gram weight.

Suitable melt flow modifiers include, but are not limited to, highmolecular weight organic acids and salts thereof, polyamides,polyesters, polyacrylates, polyurethanes, polyethers, polyureas,polyhydric alcohols, and combinations thereof. Suitable organic acidsare aliphatic organic acids, aromatic organic acids, saturatedmono-functional organic acids, unsaturated monofunctional organic acids,multi-unsaturated mono-functional organic acids, and dimerizedderivatives thereof. Particular examples of suitable organic acidsinclude, but are not limited to, caproic acid, caprylic acid, capricacid, lauric acid, stearic acid, behenic acid, erucic acid, oleic acid,linoleic acid, myristic acid, benzoic acid, palmitic acid, phenylaceticacid, naphthalenoic acid, dimerized derivatives thereof. Suitableorganic acids are more fully described, for example, in U.S. Pat. No.6,756,436, the entire disclosure of which is hereby incorporated hereinby reference. In a particular embodiment, the HNP composition comprisesan organic acid salt in an amount of 20 phr or greater, or 25 phr orgreater, or 30 phr or greater, or 35 phr or greater, or 40 phr orgreater.

Additional melt flow modifiers suitable for use in compositions of thepresent invention, include the non-fatty acid melt flow modifiersdescribed in copending U.S. patent application Ser. Nos. 11/216,725 and11/216,726, the entire disclosures of which are hereby incorporatedherein by reference.

Relatively hard/high modulus HNP compositions of the present inventionoptionally include additive(s) and/or filler(s) in an amount within arange having a lower limit of 0 or 5 or 10 wt %, and an upper limit of25 or 30 or 50 wt %, based on the total weight of the relativelyhard/high modulus HNP composition. Suitable additives and fillersinclude those previously described as suitable for the relatively softHNP compositions of the present invention.

Relatively hard/high modulus HNP compositions of the present inventionoptionally contain a low modulus HNP.

In a particular embodiment, the relatively hard/high modulus HNPcomposition has an MVTR of 8 g-mil/100 in²/day or less (i.e., 3.2g-mm/m² day or less), or 5 g-mil/100 in²/day or less (i.e., 2.0 g-mm/m²day or less), or 3 g-mil/100 in²/day or less (i.e., 1.2 g-mm/m² day orless), or 2 g-mil/100 in²/day or less (i.e., 0.8 g-mm/m² day or less),or 1 g-mil/100 in²/day or less (i.e., 0.4 g-mm/m²-day or less), or lessthan 1 g-mil/100 in²/day (i.e., less than 0.4 g-mm/m²-day). In apreferred aspect of this embodiment, the relatively hard/high modulusHNP composition comprises a high modulus HNP prepared using a cationsource which is less hydrophilic than conventional magnesium-basedcation sources. Suitable moisture resistant HNP compositions aredisclosed, for example, in copending U.S. patent application Ser. No.11/270,066 and U.S. Patent Application Publication No. 2005/0267240, theentire disclosures of which are hereby incorporated herein by reference.

In another particular embodiment, a sphere formed from the relativelyhard/high modulus HNP composition has a compression of 70 or greater, or80 or greater, or a compression within a range having a lower limit of70 or 80 or 90 or 100 and an upper limit of 110 or 130 or 140.

Relatively hard/high modulus HNP compositions of the present inventionare not limited by any particular method or any particular equipment formaking the compositions. In a preferred embodiment, the composition isprepared by the following process. The acid polymer(s), preferably anethylene/(meth) acrylic acid copolymer, optional melt flow modifier(s),and optional additive(s)/filler(s) are simultaneously or individuallyfed into a melt extruder, such as a single or twin screw extruder. Asuitable amount of cation source is then added such that at least 80%,preferably at least 90%, more preferably at least 95%, and even morepreferably at least 100%, of all acid groups present are neutralized.Optionally, the cation source is added in an amount sufficient toneutralize, theoretically, 105% or greater, or 110% or greater, or 115%or greater, or 120% or greater, or 125% or greater, or 200% or greater,or 250% or greater of all acid groups present in the composition. Theacid polymer may be at least partially neutralized prior to the aboveprocess. The components are intensively mixed prior to being extruded asa strand from the die-head.

In another preferred embodiment, the relatively hard/high modulus HNPcomposition is formed by combining a low modulus HNP with a sufficientamount of one or more additional material(s), including, but not limitedto, additives, fillers, and polymeric materials, to increase the modulussuch that the resulting composition has a modulus as described above forthe high modulus HNP.

Relatively hard/high modulus HNP compositions of the present inventionmay be blended with one or more additional polymers, such asthermoplastic polymers and elastomers.

Examples of thermoplastic polymers and elastomers suitable for blendinginclude those previously described as suitable for blending with therelatively soft/low modulus HNP compositions of the present invention.In a particular embodiment, the relatively hard/high modulus HNPcomposition comprises an acid copolymer and an additional polymercomponent, wherein the additional polymer component is a non-acidpolymer present in an amount of greater than 50 wt %, or an amountwithin a range having a lower limit of 50 or 55 or 60 or 65 or 70 and anupper limit of 80 or 85 or 90, based on the combined weight of the acidcopolymer and the non-acid polymer. In another particular embodiment,the relatively hard/high modulus HNP composition comprises an acidcopolymer and an additional polymer component, wherein the additionalpolymer component is a non-acid polymer present in an amount of lessthan 50 wt %, or an amount within a range having a lower limit of 10 or15 or 20 or 25 or 30 and an upper limit of 40 or 45 or 50, based on thecombined weight of the acid copolymer and the non-acid polymer

HNP compositions of the present invention, in the neat (i.e., unfilled)form, preferably have a specific gravity of from 0.95 g/cc to 0.99 g/cc.Any suitable filler, flake, fiber, particle, or the like, of an organicor inorganic material may be added to the HNP composition to increase ordecrease the specific gravity, particularly to adjust the weightdistribution within the golf ball, as further disclosed in U.S. Pat.Nos. 6,494,795, 6,547,677, 6,743,123, 7,074,137, and 6,688,991, theentire disclosures of which are hereby incorporated herein by reference.

In a particular embodiment, the relatively hard/high modulus HNPcomposition is formed by blending an acid polymer, a non-acid polymer, acation source, and a fatty acid or metal salt thereof.

In a particular aspect of this embodiment, the acid polymer is selectedfrom ethylene-acrylic acid and ethylene-methacrylic acid copolymers,optionally containing a softening monomer selected from n-butyl acrylateand iso-butyl acrylate. Examples of particularly suitable commerciallyavailable acid polymers include, but are not limited to, those given inTable 1 above.

In another particular aspect of this embodiment, the non-acid polymer isan elastomeric polymer. Suitable elastomeric polymers include, but arenot limited to:

-   -   (a) ethylene-alkyl acrylate polymers, particularly        polyethylene-butyl acrylate, polyethylene-methyl acrylate, and        polyethylene-ethyl acrylate;    -   (b) metallocene-catalyzed polymers;    -   (c) ethylene-butyl acrylate-carbon monoxide polymers and        ethylene-vinyl acetate-carbon monoxide polymers;    -   (d) polyethylene-vinyl acetates;    -   (e) ethylene-alkyl acrylate polymers containing a cure site        monomer;    -   (f) ethylene-propylene rubbers and ethylene-propylene-diene        monomer rubbers;    -   (g) olefinic ethylene elastomers, particularly ethylene-octene        polymers, ethylene-butene polymers, ethylene-propylene polymers,        and ethylene-hexene polymers;    -   (h) styrenic block copolymers;    -   (i) polyester elastomers;    -   (j) polyamide elastomers;    -   (k) polyolefin rubbers, particularly polybutadiene,        polyisoprene, and styrene-butadiene rubber; and    -   (l) thermoplastic polyurethanes.

Examples of particularly suitable commercially available non-acidpolymers include, but are not limited to, Lotader® ethylene-alkylacrylate polymers and Lotryl® ethylene-alkyl acrylate polymers, andparticularly Lotader® 4210, 4603, 4700, 4720, 6200, 8200, and AX8900commercially available from Arkema Corporation; Elvaloy® ACethylene-alkyl acrylate polymers, and particularly AC 1224, AC 1335, AC2116, AC3117, AC3427, and AC34035, commercially available from E. I. duPont de Nemours and Company; Fusabond® elastomeric polymers, such asethylene vinyl acetates, polyethylenes, metallocene-catalyzedpolyethylenes, ethylene propylene rubbers, and polypropylenes, andparticularly Fusabond N525, C190, C250, A560, N416, N493, N614, P614,M603, E100, E158, E226, E265, E528, and E589, commercially availablefrom E. I. du Pont de Nemours and Company; Honeywell A-C polyethylenesand ethylene maleic anhydride copolymers, and particularly A-C 5180, A-C575, A-C 573, A-C 655, and A-C 395, commercially available fromHoneywell; Nordel® IP rubber, Elite® polyethylenes, Engage® elastomers,and Amplify® functional polymers, and particularly Amplify® GR 207, GR208, GR 209, GR 213, GR 216, GR 320, GR 380, and EA 100, commerciallyavailable from The Dow Chemical Company; Enable® metallocenepolyethylenes, Exact® plastomers, Vistamaxx® propylene-based elastomers,and Vistalon® EPDM rubber, commercially available from ExxonMobilChemical Company; Starflex® metallocene linear low density polyethylene,commercially available from LyondellBasell; Elvaloy® HP4051, HP441,HP661 and HP662 ethylene-butyl acrylate-carbon monoxide polymers andElvaloy® 741, 742 and 4924 ethylene-vinyl acetate-carbon monoxidepolymers, commercially available from E. I. du Pont de Nemours andCompany; Evatane® ethylene-vinyl acetate polymers having a vinyl acetatecontent of from 18 to 42%, commercially available from ArkemaCorporation; Elvax® ethylene-vinyl acetate polymers having a vinylacetate content of from 7.5 to 40%, commercially available from E. I. duPont de Nemours and Company; Vamac® G terpolymer of ethylene,methylacrylate and a cure site monomer, commercially available from E.I. du Pont de Nemours and Company; Vistalon® EPDM rubbers, commerciallyavailable from ExxonMobil Chemical Company; Kraton® styrenic blockcopolymers, and particularly Kraton® FG1901GT, FG1924GT, and RP6670GT,commercially available from Kraton Performance Polymers Inc.; Septon®styrenic block copolymers, commercially available from Kuraray Co.,Ltd.; Hytrel® polyester elastomers, and particularly Hytrel® 3078, 4069,and 556, commercially available from E. I. du Pont de Nemours andCompany; Riteflex® polyester elastomers, commercially available fromCelanese Corporation; Pebax® thermoplastic polyether block amides, andparticularly Pebax® 2533, 3533, 4033, and 5533, commercially availablefrom Arkema Inc.; Affinity® and Affinity® GA elastomers, Versify®ethylene-propylene copolymer elastomers, and Infuse® olefin blockcopolymers, commercially available from The Dow Chemical Company;Exxelor® polymer resins, and particularly Exxelor® PE 1040, PO 1015, PO1020, VA 1202, VA 1801, VA 1803, and VA 1840, commercially availablefrom ExxonMobil Chemical Company; and Royaltuf® EPDM, and particularlyRoyaltuf®498 maleic anhydride modified polyolefin based on an amorphousEPDM and Royaltuf®485 maleic anhydride modified polyolefin based on ansemi-crystalline EPDM, commercially available from Chemtura Corporation.

Additional examples of particularly suitable commercially availableelastomeric polymers include, but are not limited to, those given inTable 2 above.

The acid polymer and non-acid polymer are combined and reacted with acation source, such that at least 80% of all acid groups present areneutralized. The present invention is not meant to be limited by aparticular order for combining and reacting the acid polymer, non-acidpolymer and cation source. In a particular embodiment, the fatty acid ormetal salt thereof is used in an amount such that the fatty acid ormetal salt thereof is present in the HNP composition in an amount offrom 10 wt % to 60 wt %, or within a range having a lower limit of 10 or20 or 30 or 40 wt % and an upper limit of 40 or 50 or 60 wt %, based onthe total weight of the HNP composition. Suitable cation sources andfatty acids and metal salts thereof are further disclosed above.

In another particular aspect of this embodiment, the acid polymer is anethylene-acrylic acid polymer having an acid content of 19 wt % orgreater, the non-acid polymer is a metallocene-catalyzed ethylene-butenecopolymer, optionally modified with maleic anhydride, the cation sourceis magnesium, and the fatty acid or metal salt thereof is magnesiumoleate present in the composition in an amount of 20 to 50 wt %, basedon the total weight of the composition.

The relatively hard/high modulus HNP composition optionally comprisesfrom 0.5 wt % to 80 wt % of a plasticizer, based on the total weight ofthe composition. Suitable plasticizers are disclosed further below.

Plasticized Acid Copolymer Composition

Golf balls of the present invention comprise at least one layer formedfrom a plasticized acid copolymer composition. The plasticized acidcopolymer composition is selected from (a) relatively soft/low modulusHNP compositions, as described above, additionally comprising from 0.5wt % to 80 wt % of a plasticizer selected from the plasticizersdescribed below, (b) relatively hard/high modulus HNP compositions, asdescribed above, additionally comprising from 0.5 wt % to 80 wt % of aplasticizer selected from the plasticizers described below, and (c) theplasticized acid copolymer compositions described below.

Suitable plasticized acid copolymer compositions are formed by combiningan acid polymer, which is optionally partially or fully neutralized,with 0.5 wt % to 80 wt % of a plasticizer, based on the total weight ofthe composition.

The acid copolymer of the plasticized acid copolymer composition is acopolymer of an α-olefin and a C₃-C₈ α,β-ethylenically unsaturatedcarboxylic acid, optionally including a softening monomer selected fromthe group consisting of alkyl acrylates and methacrylates. It isunderstood that the acid copolymer may be a blend of two or moredifferent acid copolymers. The α-olefin is typically present in the acidcopolymer in an amount of about 15 wt % or greater, or 25 wt % orgreater, or 40 wt % or greater, or 60 wt % or greater, or 75 wt % orgreater, or 79 wt % or greater, or 81 wt % or greater, or 85 wt % orgreater, or 90 wt % or greater, or 94 wt % or greater, or 97 wt % orgreater, or 98 wt % or greater, based on the total weight of the acidcopolymer. The acid is typically present in the acid copolymer in anamount of 1 or 8 or 10 or 12 or 15 or 19 or 20 or 25 or 30 or 35 or 40wt %, based on the total weight of the acid copolymer. The α-olefin ispreferably selected from ethylene and propylene. The acid is preferablyselected from (meth) acrylic acid, ethacrylic acid, maleic acid,crotonic acid, fumaric acid, and itaconic acid. (Meth) acrylic acid isparticularly preferred. The optional softening monomer is preferablyselected from (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth)acrylate, methyl (meth) acrylate, and ethyl (meth) acrylate.

Suitable acid copolymers are further disclosed, for example, in U.S.Pat. Nos. 6,953,820, 6,815,480, 6,762,246, 6,777,472, 6,562,906,6,653,382, 5,691,418, and U.S. Patent Application Publication Nos.2005/0148725, 2005/0049367, 2005/0020741, 2004/0220343, and2003/0130434, the entire disclosures of which are hereby incorporatedherein by reference.

Suitable acid copolymers also include partially and fully neutralizedacid polymers, wherein the acid copolymer is reacted with a cationsource, prior to and/or during the process of forming the plasticizedacid copolymer composition, optionally in the presence of a highmolecular weight organic acid or salt thereof, such that at least 70%,or at least 80%, or at least 90%, or at least 95%, or 100%, of all acidgroups present in the plasticized acid copolymer composition areneutralized. The present invention is not meant to be limited by aparticular order for combining and reacting the acid copolymer andcation source. The partially or highly neutralized acid copolymer may bediluted with a second acid copolymer to reduce the level ofneutralization in the final composition.

Suitable cation sources include, but are not limited to, metal ions andcompounds of alkali metals, alkaline earth metals, and transitionmetals; metal ions and compounds of rare earth elements; ammonium saltsand monoamine salts; and combinations thereof. Preferred cation sourcesare metal ions and compounds of magnesium, sodium, potassium, cesium,calcium, barium, manganese, copper, zinc, tin, lithium, and rare earthmetals.

Suitable high molecular weight organic acids and salts thereof arealiphatic organic acids, aromatic organic acids, saturatedmono-functional organic acids, unsaturated monofunctional organic acids,multi-unsaturated mono-functional organic acids, dimerized derivativesthereof, the salts particularly the barium, lithium, sodium, zinc,bismuth, chromium, cobalt, copper, potassium, strontium, titanium,tungsten, magnesium, and calcium salts thereof, and blends of two ormore thereof. Particular examples of suitable organic acids include, butare not limited to, caproic acid, caprylic acid, capric acid, lauricacid, stearic acid, behenic acid, erucic acid, oleic acid, linoleicacid, myristic acid, benzoic acid, palmitic acid, phenylacetic acid,naphthalenoic acid, dimerized derivatives thereof, salts thereof, andblends of two or more thereof. Suitable organic acids are more fullydescribed, for example, in U.S. Pat. No. 6,756,436, the entiredisclosure of which is hereby incorporated herein by reference. In aparticular embodiment, the organic acid or salt thereof is used in anamount such that the organic acid or salt thereof is present in theplasticized acid copolymer composition in an amount of 10 wt % orgreater, or 20 wt % or greater, or 30 wt % or greater, or 40 wt % orgreater, or 50 wt % or greater, or 60 wt % or greater, based on thetotal weight of the plasticized acid copolymer composition.

Examples of suitable commercially available acid copolymers includethose given in Table 1 above. Examples of suitable commerciallyavailable partially and fully neutralized acid polymers include, but arenot limited to, Surlyn® ionomers, commercially available from E. I. duPont de Nemours and Company; AClyn® ionomers, commercially availablefrom Honeywell International Inc.; Iotek® ionomers, commerciallyavailable from ExxonMobil Chemical Company; and DuPont® HPF 1000, HPF2000, HPF AD1035, and HPF AD1035 Soft, ionomeric materials commerciallyavailable from E. I. du Pont de Nemours and Company.

The plasticized acid copolymer composition comprises from 0.5 to 80 wt%, based on the total weight of the composition, of a plasticizer.

In a particular embodiment, the plasticizer is selected fromN-butylbenzenesulfonamide (BBSA); N-ethylbenzenesulfonamide (EBSA);N-propylbenzenesulfonamide (PBSA); N-butyl-N-dodecylbenzenesulfonamide(BDBSA); N,N-dimethylbenzenesulfonamide (DMBSA);p-methylbenzenesulfonamide; o,p-toluene sulfonamide; p-toluenesulfonamide; 2-ethylhexyl-4-hydroxybenzoate;hexadecyl-4-hydroxybenzoate; 1-butyl-4-hydroxybenzoate; dioctylphthalate; diisodecyl phthalate; di-(2-ethylhexyl) adipate; andtri-(2-ethylhexyl) phosphate.

In another particular embodiment, the plasticizer is selected frompolytetramethylene ether glycol, e.g., PolyTHF™ 250, commerciallyavailable from BASF; propylene carbonate, e.g., Jeffsol™ PC propylenecarbonate, commercially available from Huntsman Corp.; dipropyleneglycoldibenzoate, e.g., Benzoflex™ 284 plasticizer, commercially availablefrom Eastman Chemical; and combinations of two or more thereof.

In another particular embodiment, the plasticizer is selected frombenzene mono-, di-, and tricarboxylic acid esters; phthalates, such asbis(2-ethylhexyl) phthalate (DEHP), diisononyl phthalate (DINP),di-n-butyl phthalate (DnBP, DBP), butyl benzyl phthalate (BBP),diisodecyl phthalate (DIDP), dioctyl phthalate (DnOP), diisooctylphthalate (DIOP), diethyl phthalate (DEP), diisobutyl phthalate (DIBP),and di-n-hexyl phthalate; iso- and terephthalates, such as dioctylterephthalate and dinonyl isophthalate; trimellitates, such as trimethyltrimellitate (TMTM), tri-(2-ethylhexyl) trimellitate (TOTM),tri-(n-octyl,n-decyl) trimellitate, tri-(heptyl,nonyl) trimellitate,tri-n-octyl trimellitate; and benzoates, such as 2-ethylhexyl-4-hydroxybenzoate, n-octyl benzoate, methyl benzoate, and ethyl benzoate; andcombination of two or more thereof.

In another particular embodiment, the plasticizer is selected from alkyldiacid esters commonly based on C4-C12 alkyl dicarboxylic acids, such asadipic, sebacic, azelaic, and maleic acids, e.g.,bis(2-ethylhexyl)adipate (DEHA), dimethyl adipate (DMAD), monomethyladipate (MMAD), dioctyl adipate (DOA), dibutyl sebacate (DBS), dibutylmaleate (DBM), diisobutyl maleate (DIBM), dioctyl sebacate (DOS), estersbased on glycols, polyglycols and polyhydric alcohols, such aspoly(ethylene glycol), mono- and di-esters, cyclohexanedimethanolesters, sorbitol derivatives, and triethylene glycol dihexanoate,diethylene glycol di-2-ethylhexanoate, tetraethylene glycoldiheptanoate, and ethylene glycol dioleate.

In another particular embodiment, the plasticizer is selected from fattyacids, fatty acid salts, fatty acid amides, and fatty acid esters,including, for example, compounds such as stearic, oleic, ricinoleic,behenic, myristic, linoleic, palmitic, and lauric acid esters, salts,and mono- and bis-amides. Suitable fatty acid salts include, forexample, metal stearates, erucates, laurates, oleates, palmitates,pelargonates, and the like. Also suitable are fatty alcohols andacetylated fatty alcohols, and carbonate esters, such as propylenecarbonate and ethylene carbonate. Particularly suitable are, forexample, alkyl oleates selected from methyl, ethyl, propyl, butyl,octyl, and decyl oleates. In a particular aspect of this embodiment, theplasticizer is selected from ethyl oleate, butyl oleate, octyl oleat,and 2-ethyl hexyl oleate. Also particularly suitable are butyl stearate,methyl acetylricinoleate, zinc oleate, ethylene bis-oleamide, stearylerucamide, zinc stearate, calcium stearate, magnesium stearate, bariumstearate.

In another particular embodiment, the plasticizer is selected fromglycerol-based esters, such as soy-bean, tung, or linseed oils, andtheir epoxidized derivatives; polymeric polyester plasticizers formedfrom the esterification reaction of diacids and diglycols; and thering-opening polymerization reaction of caprolactones with diacids ordiglycols. Citrate esters and acetylated citrate esters are particularlysuitable. Glycerol mono-, di-, and tri-oleates are also particularlysuitable.

In another particular embodiment, the plasticizer is selected fromdicarboxylic acid molecules containing both a carboxylic acid ester anda carboxylic acid salt, such as the magnesium salt of mono-methyladipate and the zinc salt of mono-octyl glutarate; tri- andtetra-carboxylic acid esters and salts.

In another particular embodiment, the plasticizer is selected fromorganophosphate and organosulfur compounds, such as tricresyl phosphate(TCP), tributyl phosphate(TBP), alkyl sulfonic acid phenyl esters (ASE);sulfonamides, such as N-ethyl toluene sulfonamide, N-(2-hydroxypropyl)benzene sulfonamide, N-(n-butyl) benzene sulfonamide; and thioester andthioether variants thereof.

In another particular embodiment, the plasticizer is selected fromalcohols, glycols, polyglycols, and polyethers, such aspolytetramethylene ether glycol, poly(ethylene glycol), andpoly(propylene glycol), oleyl alchohol, and cetyl alcohol.

In another particular embodiment, the plasticizer is selected fromsaturated and unsaturated, linear and cyclic, halogenated andnon-halogenated hydrocarbons, and particularly mineral oils,microcrystalline waxes, and low-molecular weight polybutadiene.

In another particular embodiment, the plasticizer is selected frombutylbenzenesulphonamide (BBSA), ethylhexyl para-hydroxybenzoate (EHPB)and decylhexyl para-hydroxybenzoate (DHPB), as disclosed in U.S. Pat.No. 6,376,037 to Montanari et al., the entire disclosure of which ishereby incorporated herein by reference.

In another particular embodiment, the plasticizer is selected fromesters and alkylamides, such as phthalic acid esters, including, forexample, dimethyl phthalate, diethyl phthalate, dibutyl phthalate,diheptyl phthalate, di-2-ethylhexyl phthalate, di-n-octyl phthalate,diisodecyl phthalate, ditridecyl phthalate, dicyclohexyl phthalate,butylbenzyl phthalate, diisononyl phthalate, ethylphthalylethylglycolate, butylphthalylbutyl glycolate, diundecyl phthalate, anddi-2-ethylhexyl tetrahydrophthalate, and those disclosed in U.S. Pat.No. 6,538,099 to Isobe et al., the entire disclosure of which is herebyincorporated herein by reference.

In another particular embodiment, the plasticizer is selected fromsulphonamides such as N-butylbenzenesulphonamide,ethyltoluene-suiphonamide, N-cyclohexyltoluenesulphonamide,2-ethylhexyl-para-hydroxybenzoate, 2-decylhexyl-para-hydroxybenzoate,oligoethyleneoxytetrahydrofurfuryl alcohol, and oligoethyleneoxymalonate; esters of hydroxybenzoic acid; esters and ethers oftetrahydrofurfuryl alcohol, and esters of citric acid or hydroxymalonicacid; and those disclosed in U.S. Pat. No. 7,045,185 to Jacques et al,the entire disclosure of which is hereby incorporated herein byreference.

In another particular embodiment, the plasticizer is selected fromsulfonamides, such as N-alkyl benzenesulfonamides andtoluenesufonamides, and particularly N-butylbenzenesulfonamide,N-(2-hydroxypropyl)benzenesulfonamide, N-ethyl-o-toluenesulfonamide,N-ethyl-p-toluenesulfonamide, o-toluenesulfonamide,p-toluenesulfonamide, and the sulfonamides disclosed in U.S. Pat. No.7,297,737 to Fish, Jr. et al., and U.S. Patent Application PublicationNo. 2010/0183837 to Hochstetter et al., the entire disclosures of whichare hereby incorporated herein by reference.

The plasticizer is preferably present in the plasticized acid copolymercomposition in an amount sufficient to substantially change thestiffness and/or hardness of the acid copolymer. In a particularembodiment, the plasticizer is present in an amount of 0.5% or 1% or 3%or 5% or 7% or 8% or 9% or 10% or 12% or 15% or 18% or 20% or 22% or 25%or 30% or 35% or 40% or 42% or 50% or 55% or 60% or 66% or 71% or 75% or80%, by weight based on the total weight of the plasticized acidcopolymer composition, or the plasticizer is present in an amount withina range having a lower limit and an upper limit selected from thesevalues.

In a particular embodiment, a non-plasticized composition comprising anethylene acid copolymer has a first flexural modulus value, aplasticized composition consisting of the non-plasticized compositionand from 0.5 wt % to 80 wt % of a plasticizer has a second flexuralmodulus value, wherein the second flexural modulus value is at least 1%less; or at least 2% less; or at least 4% less; or at least 8% less; orat least 10% less than the first flexural modulus value. In a particularaspect of this embodiment, the plasticized composition has a flexuralmodulus of about 500 psi (or less), or a flexural modulus of 1,000 psior 1,600 psi or 2,000 psi or 4,200 psi or 7,500 psi or 9,000 psi or10,000 psi or 20,000 psi or 40,000 psi or 50,000 psi or 60,000 psi or70,000 psi or 80,000 psi or 90,000 psi or 100,000 psi or 110,000 psi or120,000 psi or 130,000 psi or 140,000 psi or 160,000 psi or 180,000 psior 200,000 psi or 300,000 psi, or a flexural modulus within a rangehaving a lower limit and an upper limit selected from these values.

In another particular embodiment, a non-plasticized compositioncomprising an ethylene acid copolymer has a first Tg value, aplasticized composition consisting of the non-plasticized compositionand from 0.5 wt % to 80 wt % of a plasticizer has a second Tg value,wherein the second Tg value is at least 10 less, or at least 20 less, orat least 40 less, or at least 80 less, or at least 10° less than thefirst Tg value, or the second Tg value is within 1° of the first Tgvalue.

In another particular embodiment, a non-plasticized compositioncomprising an ethylene acid copolymer has a first compression, aplasticized composition consisting of the non-plasticized compositionand from 0.5 wt % to 80 wt % of a plasticizer has a second compression,wherein the second compression is equal to or less than the firstcompression.

In a particular embodiment, the plasticized acid copolymer compositionhas a Shore D hardness of 5 or 8 or 10 or 12 or 14 or 28 or 30 or 32 or34 or 35 or 38 or 40, or a Shore D hardness within a range having alower limit and an upper limit of these values.

In another particular embodiment, the plasticized acid copolymercomposition has a Shore C hardness of 10 or 13 or 15 or 17 or 19 or 44or 46 or 48 or 50 or 53 or 55, or a Shore C hardness within a rangehaving a lower limit and an upper limit of these values.

In another particular embodiment, the plasticized acid copolymercomposition has a Shore D hardness of 25 or 28 or 30 or 32 or 35 or 36or 38 or 40 or 42 or 45 or 48 or 50 or 54 or 56 or 60, or a Shore Dhardness within a range having a lower limit and an upper limit of thesevalues.

In another particular embodiment, the plasticized acid copolymercomposition has a Shore C hardness of 30 or 33 or 35 or 37 or 39 or 41or 43 or 62 or 64 or 66 or 68 or 71 or 73 or 75, or a Shore C hardnesswithin a range having a lower limit and an upper limit of these values.

In another particular embodiment, the plasticized acid copolymercomposition has a Shore D hardness of 42 or 44 or 47 or 51 or 53 or 58or 60 or 65 or 72 or 77 or 80 or 84 or 91 or 95, or a Shore D hardnesswithin a range having a lower limit and an upper limit of these values.

In another particular embodiment, the plasticized acid copolymercomposition has a Shore C hardness of 57 or 59 or 62 or 66 or 72 or 75or 78 or 84 or 87 or 90 or 93 or 95 or 97 or 99, or a Shore C hardnesswithin a range having a lower limit and an upper limit of these values.

Plasticized acid copolymer compositions of the present invention are notlimited by any particular method or any particular equipment for makingthe compositions. In a particular embodiment, the composition isprepared by the following process. The acid copolymer, which isoptionally already partially or fully neutralized, plasticizer, andoptionally one or more of: non-acid polymer, melt-flow modifier, andadditive/filler are simultaneously or individually fed into a meltextruder, such as a single or twin screw extruder. If the level ofneutralization of the acid polymer is to be increased, a suitable amountof cation source is added to achieve the desired level ofneutralization. The components are intensively mixed prior to beingextruded as a strand from the die-head. Methods for incorporatingplasticizer into the thermoplastic compositions described herein arefurther disclosed in co-pending U.S. patent application Ser. No.13/929,841, and in U.S. Pat. Nos. 8,523,708 and 8,523,709, the entiredisclosures of which are hereby incorporated herein by reference.

In a particular embodiment, the plasticized acid copolymer compositionis formed by blending an acid polymer, a non-acid polymer, a cationsource, and a high molecular weight organic acid or salt thereof, andcombining the resulting composition with a plasticizer. For purposes ofthe present invention, maleic anhydride modified polymers are definedherein as a non-acid polymer despite having anhydride groups that canring-open to the acid form during processing of the polymer to form theHNP compositions herein. The maleic anhydride groups are grafted onto apolymer, are present at relatively very low levels, and are not part ofthe polymer backbone, as is the case with the acid copolymers.

Suitable non-acid polymer(s) are preferably selected from the groupconsisting of polyolefins, polyamides, polyesters, polyethers,polyurethanes, metallocene-catalyzed polymers, single-site catalystpolymerized polymers, ethylene propylene rubber, ethylene propylenediene rubber, styrenic block copolymer rubbers, alkyl acrylate rubbers,chlorinated polyethylene, polyvinyl chloride, chlorinated polyvinylchloride, and functionalized derivatives thereof.

In a particular embodiment, the non-acid polymer is an elastomericpolymer selected from the group consisting of:

-   -   (a) ethylene-alkyl acrylate polymers, particularly        polyethylene-butyl acrylate, polyethylene-methyl acrylate, and        polyethylene-ethyl acrylate;    -   (b) metallocene-catalyzed polymers;    -   (c) ethylene-butyl acrylate-carbon monoxide polymers and        ethylene-vinyl acetate-carbon monoxide polymers;    -   (d) polyethylene-vinyl acetates;    -   (e) ethylene-alkyl acrylate polymers containing a cure site        monomer;    -   (f) ethylene-propylene rubbers and ethylene-propylene-diene        monomer rubbers;    -   (g) olefinic ethylene elastomers, particularly ethylene-octene        polymers, ethylene-butene polymers, ethylene-propylene polymers,        and ethylene-hexene polymers;    -   (h) styrenic block copolymers;    -   (i) polyester elastomers;    -   (j) polyamide elastomers;    -   (k) polyol efin rubbers, particularly polybutadiene,        polyisoprene, and styrene-butadiene rubber; and    -   (l) thermoplastic polyurethanes.

Examples of particularly suitable commercially available non-acidpolymers include, but are not limited to, Lotader® ethylene-alkylacrylate polymers and Lotryl® ethylene-alkyl acrylate polymers, andparticularly Lotader® 4210, 4603, 4700, 4720, 6200, 8200, and AX8900commercially available from Arkema Corporation; Elvaloy® ACethylene-alkyl acrylate polymers, and particularly AC 1224, AC 1335, AC2116, AC3117, AC3427, and AC34035, commercially available from E. I. duPont de Nemours and Company; Fusabond® elastomeric polymers, such asethylene vinyl acetates, polyethylenes, metallocene-catalyzedpolyethylenes, ethylene propylene rubbers, and polypropylenes, andparticularly Fusabond N525, C190, C250, A560, N416, N493, N614, P614,M603, E100, E158, E226, E265, E528, and E589, commercially availablefrom E. I. du Pont de Nemours and Company; Honeywell A-C polyethylenesand ethylene maleic anhydride copolymers, and particularly A-C 5180, A-C575, A-C 573, A-C 655, and A-C 395, commercially available fromHoneywell; Nordel® IP rubber, Elite® polyethylenes, Engage® elastomers,and Amplify® functional polymers, and particularly Amplify® GR 207, GR208, GR 209, GR 213, GR 216, GR 320, GR 380, and EA 100, commerciallyavailable from The Dow Chemical Company; Enable® metallocenepolyethylenes, Exact® plastomers, Vistamaxx® propylene-based elastomers,and Vistalon® EPDM rubber, commercially available from ExxonMobilChemical Company; Starflex® metallocene linear low density polyethylene,commercially available from LyondellBasell; Elvaloy® HP4051, HP441,HP661 and HP662 ethylene-butyl acrylate-carbon monoxide polymers andElvaloy® 741, 742 and 4924 ethylene-vinyl acetate-carbon monoxidepolymers, commercially available from E. I. du Pont de Nemours andCompany; Evatane® ethylene-vinyl acetate polymers having a vinyl acetatecontent of from 18 to 42%, commercially available from ArkemaCorporation; Elvax® ethylene-vinyl acetate polymers having a vinylacetate content of from 7.5 to 40%, commercially available from E. I. duPont de Nemours and Company; Vamac® G terpolymer of ethylene,methylacrylate and a cure site monomer, commercially available from E.I. du Pont de Nemours and Company; Vistalon® EPDM rubbers, commerciallyavailable from ExxonMobil Chemical Company; Kraton® styrenic blockcopolymers, and particularly Kraton® FG1901GT, FG1924GT, and RP6670GT,commercially available from Kraton Performance Polymers Inc.; Septon®styrenic block copolymers, commercially available from Kuraray Co.,Ltd.; Hytrel® polyester elastomers, and particularly Hytrel® 3078, 4069,and 556, commercially available from E. I. du Pont de Nemours andCompany; Riteflex® polyester elastomers, commercially available fromCelanese Corporation; Pebax® thermoplastic polyether block amides, andparticularly Pebax® 2533, 3533, 4033, and 5533, commercially availablefrom Arkema Inc.; Affinity® and Affinity® GA elastomers, Versify®ethylene-propylene copolymer elastomers, and Infuse® olefin blockcopolymers, commercially available from The Dow Chemical Company;Exxelor® polymer resins, and particularly Exxelor® PE 1040, PO 1015, PO1020, VA 1202, VA 1801, VA 1803, and VA 1840, commercially availablefrom ExxonMobil Chemical Company; and Royaltuf® EPDM, and particularlyRoyaltuf®498 maleic anhydride modified polyolefin based on an amorphousEPDM and Royaltuf®485 maleic anhydride modified polyolefin based on ansemi-crystalline EPDM, commercially available from Chemtura Corporation.

Additional examples of particularly suitable commercially availableelastomeric non-acid polymers include, but are not limited to, thosegiven in Table 2 above.

In a particular embodiment, the plasticized acid copolymer compositionis formed by blending an ethylene-acrylic acid polymer, ametallocene-catalyzed ethylene-butene copolymer optionally modified withmaleic anhydride, a magnesium cation source, and 20 to 50 wt % magnesiumoleate, and combining the resulting composition with a plasticizerselected from the plasticizers described above.

In another particular embodiment, the plasticized acid copolymercomposition is formed by blending a highly neutralized polymer, such asDuPont HPF 2000 with 10 to 40 wt % of a fatty acid ester, such as ethyloleate or butyl oleate.

Plasticized acid copolymer compositions of the present inventionoptionally include additives(s) and/or filler(s), such as chemicalblowing and foaming agents, optical brighteners, coloring agents,fluorescent agents, whitening agents, UV absorbers, light stabilizers,defoaming agents, processing aids, mica, talc, nano-fillers,antioxidants, stabilizers, softening agents, fragrance components,plasticizers, impact modifiers, TiO₂, acid copolymer wax, surfactants,and fillers, such as zinc oxide, tin oxide, barium sulfate, zincsulfate, calcium oxide, calcium carbonate, zinc carbonate, bariumcarbonate, clay, tungsten, tungsten carbide, silica, lead silicate,regrind (recycled material), and mixtures thereof.

Golf Ball Applications

Golf balls of the present invention comprise at least one layer formedfrom a relatively soft HNP composition and at least one layer formedfrom a relatively hard HNP composition, or at least one layer formedfrom a relatively low modulus HNP composition and at least one layerformed from a relatively high modulus HNP composition.

In one embodiment, the present invention provides a golf ball having amulti-layer core and a cover, wherein the core includes a layer formedfrom a relatively soft HNP composition and a layer formed from arelatively hard HNP composition. In a particular aspect of thisembodiment, the relatively soft HNP composition is plasticized. Inanother particular aspect of this embodiment, the relatively hard HNPcomposition is plasticized. In another particular aspect of thisembodiment, the relatively soft HNP composition and the relatively hardHNP composition are plasticized.

In another embodiment, the present invention provides a golf ball havinga dual-layer core and a cover, wherein the dual-layer core includes alayer formed from a low modulus HNP composition and a layer formed froma high modulus HNP composition. In a particular aspect of thisembodiment, the relatively low modulus HNP composition is plasticized.In another particular aspect of this embodiment, the relatively highmodulus HNP composition is plasticized. In another particular aspect ofthis embodiment, the relatively low modulus HNP composition and therelatively high modulus HNP composition are plasticized.

Optionally, the soft (or low modulus HNP composition) and/or the hard(or high modulus) HNP composition is replaced with a differentplasticized acid copolymer composition. Thus, in one embodiment, thegolf ball includes a layer formed from a soft (or low modulus) HNPcomposition and a plasticized acid copolymer composition, and, inanother embodiment, the golf ball includes a layer formed from a hard(or high modulus) HNP composition and a plasticized acid copolymercomposition.

In the embodiments disclosed herein, the relatively soft/low modulus HNPcomposition and/or the relatively hard/high modulus HNP compositionand/or the plasticized acid copolymer composition can be either foamedor filled with density adjusting materials to provide desirable golfball performance characteristics.

Golf balls having a layer formed from a relatively soft HNP compositionand a layer formed from a relatively hard HNP composition are furtherdisclosed, for example, in U.S. Patent Application Publication No.2007/0207880, the entire disclosure of which is hereby incorporatedherein by reference.

Golf balls having a layer formed from a low modulus HNP composition anda layer formed from a high modulus HNP composition are furtherdisclosed, for example, in U.S. Pat. No. 7,211,008, the entiredisclosure of which is hereby incorporated herein by reference.

In one embodiment, the present invention provides a golf ball having amulti-layer core, wherein the core comprises a center, an outer corelayer, and an intermediate core layer disposed between the center andthe outer core layer. Each one of the core layers, including the center,may be formed from a composition disclosed herein or a blend ofcompositions disclosed herein, so long as at least one layer is formedfrom a relatively soft (or low modulus) HNP composition and at least onelayer is formed from a relatively hard (or high modulus) HNPcomposition, wherein at least one of the relatively soft or relativelyhard HNP compositions is optionally plasticized, or, alternatively, atleast one layer is formed from a soft HNP composition or hard HNPcomposition and at least one layer is formed from a plasticized acidcopolymer composition. The multi-layer core optionally comprises two ormore layers formed from the same or different relatively soft HNPcompositions and/or two or more layers formed from the same or differentrelatively hard HNP compositions and/or two or more layers formed fromthe same or different plasticized acid copolymer compositions.

In a particular aspect of this embodiment, the intermediate core layeris formed from a relatively hard HNP composition and the outer corelayer is formed from a relatively soft HNP composition, wherein at leastone of the relatively soft or relatively hard HNP compositions isoptionally plasticized.

In another particular aspect of this embodiment, the intermediate corelayer is formed from a relatively soft HNP composition and the outercore layer is formed from a relatively hard HNP composition, wherein atleast one of the relatively soft or relatively hard HNP compositions isoptionally plasticized.

In another particular aspect of this embodiment, the intermediate corelayer is formed from a relatively hard HNP composition, which isoptionally plasticized, and the outer core layer is formed from aplasticized acid copolymer composition.

In another particular aspect of this embodiment, the intermediate corelayer is formed from a relatively soft HNP composition, which isoptionally plasticized, and the outer core layer is formed from aplasticized acid copolymer composition.

In another particular aspect of this embodiment, the intermediate corelayer is formed from a plasticized acid copolymer composition and theouter core layer is formed from a relatively hard HNP composition, whichis optionally plasticized.

In another particular aspect of this embodiment, the intermediate corelayer is formed from a plasticized acid copolymer composition and theouter core layer is formed from a relatively soft HNP composition, whichis optionally plasticized.

In another particular aspect of this embodiment, the center is formedfrom a relatively soft HNP composition and the intermediate core layeris formed from a relatively hard HNP composition, wherein at least oneof the relatively soft or relatively hard HNP compositions is optionallyplasticized.

In another particular aspect of this embodiment, the center is formedfrom a relatively hard HNP composition and the intermediate core layeris formed from a relatively soft HNP composition, wherein at least oneof the relatively soft or relatively hard HNP compositions is optionallyplasticized.

In another particular aspect of this embodiment, the center is formedfrom a relatively hard HNP composition, which is optionally plasticized,and the intermediate core layer is formed from a plasticized acidcopolymer composition.

In another particular aspect of this embodiment, the center is formedfrom a relatively soft HNP composition, which is optionally plasticized,and the intermediate core layer is formed from a plasticized acidcopolymer composition.

In another particular aspect of this embodiment, the center is formedfrom a plasticized acid copolymer composition and the intermediate corelayer is formed from a relatively hard HNP composition, which isoptionally plasticized.

In another particular aspect of this embodiment, the center is formedfrom a plasticized acid copolymer composition and the intermediate corelayer is formed from a relatively soft HNP composition, which isoptionally plasticized.

In another particular aspect of this embodiment, the center is formedfrom a relatively soft HNP composition and the outer core layer isformed from a relatively hard HNP composition, wherein at least one ofthe relatively soft or relatively hard HNP compositions is optionallyplasticized.

In another particular aspect of this embodiment, the center is formedfrom a relatively hard HNP composition and the outer core layer isformed from a relatively soft HNP composition, wherein at least one ofthe relatively soft or relatively hard HNP compositions is optionallyplasticized.

In another particular aspect of this embodiment, the center is formedfrom a relatively hard HNP composition, which is optionally plasticized,and the outer core layer is formed from a plasticized acid copolymercomposition.

In another particular aspect of this embodiment, the center is formedfrom a relatively soft HNP composition, which is optionally plasticized,and the outer core layer is formed from a plasticized acid copolymercomposition.

In another particular aspect of this embodiment, the center is formedfrom a plasticized acid copolymer composition and the outer core layeris formed from a relatively hard HNP composition, which is optionallyplasticized.

In another particular aspect of this embodiment, the center is formedfrom a plasticized acid copolymer composition and the outer core layeris formed from a relatively soft HNP composition, which is optionallyplasticized.

In another embodiment, the present invention provides a golf ball havinga dual-layer core, wherein the core includes a center and an outer corelayer. In a particular aspect of this embodiment, the center is formedfrom a low modulus HNP composition and the outer core layer is formedfrom a high modulus HNP composition, wherein at least one of the lowmodulus or high modulus HNP compositions is optionally plasticized. Inanother particular aspect of this embodiment, the center is formed froma high modulus HNP composition and the outer core layer is formed from alow modulus HNP composition, wherein at least one of the low modulus orhigh modulus HNP compositions is optionally plasticized.

In another embodiment, the present invention provides a golf ball havinga dual- or multi-layer core, wherein the core includes a center and anouter core layer. In a particular aspect of this embodiment, the centeris formed from a relatively soft HNP composition and the outer corelayer is formed from a relatively hard HNP composition, wherein at leastone of the relatively soft or relatively hard HNP compositions isoptionally plasticized. In another particular aspect of this embodiment,the center is formed from a relatively hard HNP composition and theouter core layer is formed from a relatively soft HNP composition,wherein at least one of the relatively soft or relatively hard HNPcompositions is optionally plasticized. In another particular aspect ofthis embodiment, the center is formed from a relatively soft HNPcomposition and the outer core layer is formed from an acid copolymercomposition, at least one of which is plasticized. In another particularaspect of this embodiment, the center is formed from a relatively hardHNP composition and the outer core layer is formed from an acidcopolymer composition, at least one of which is plasticized. In anotherparticular aspect of this embodiment, the center is formed from an acidcopolymer composition and the outer core layer is formed from arelatively soft HNP composition, at least one of which is plasticized.In another particular aspect of this embodiment, the center is formedfrom an acid copolymer composition and the outer core layer is formedfrom a relatively hard HNP composition, at least one of which isplasticized. In a further aspect of these particular embodiments, thecore optionally includes an intermediate core layer formed from a rubbercomposition, and/or the ball optionally includes a rubber intermediatelayer disposed between the core and the cover.

In embodiments of the present invention wherein the core includes alayer formed from a composition other than a relatively soft HNPcomposition or a relatively hard HNP composition, such layer may beformed from any suitable golf ball composition. Preferably, the layerthat is not formed from a relatively soft HNP composition or arelatively hard HNP composition is formed from a rubber composition orfrom a highly resilient thermoplastic polymer such as a conventional HNPcomposition. Particularly suitable thermoplastic polymers includeSurlyn® ionomers, Hytrel® thermoplastic polyester elastomers, andionomeric materials sold under the trade names DuPont® HPF 1000, HPF2000, HPF AD 1035, HPF AD 1040, all of which are commercially availablefrom E. I. du Pont de Nemours and Company; Iotek® ionomers, commerciallyavailable from ExxonMobil Chemical Company; and Pebax® thermoplasticpolyether block amides, commercially available from Arkema Inc. Suitablerubber and thermoplastic polymer compositions are further disclosedbelow.

In one embodiment, the present invention is directed to a golf ballcomprising a center, an outer core layer, an intermediate core layerdisposed between the center and the outer core layer, and one or morecover layers. In a particular aspect of this embodiment, the golf ballhas one or more of the following properties:

-   -   (a) a center having a diameter within a range having a lower        limit of 0.250 or 0.500 or 0.600 or 0.750 or 0.800 or 1.000 or        1.100 or 1.200 inches and an upper limit of 1.300 or 1.350 or        1.400 or 1.500 or 1.510 or 1.530 or 1.550 or 1.570 or 1.580 or        1.600 inches;    -   (b) an intermediate core layer having a thickness within a range        having a lower limit of 0.020 or 0.025 or 0.032 or 0.050 or        0.075 or 0.100 or 0.125 inches and an upper limit of 0.150 or        0.175 or 0.200 or 0.220 or 0.250 or 0.280 or 0.300 inches;    -   (c) an outer core layer having a thickness within a range having        a lower limit of 0.010 or 0.020 or 0.025 or 0.030 or 0.032        inches and an upper limit of 0.070 or 0.080 or 0.100 or 0.150 or        0.310 or 0.440 or 0.560 inches;    -   (d) an intermediate core layer and an outer core layer having a        combined thickness within a range having a lower limit of 0.040        inches and an upper limit of 0.560 or 0.800 inches;    -   (e) an outer core layer having a thickness such that a golf ball        subassembly including the center, intermediate core layer, and        core layer has an outer diameter within a range having a lower        limit of 1.000 or 1.300 or 1.400 or 1.450 or 1.500 or 1.510 or        1.530 or 1.550 inches and an upper limit of 1.560 or 1.570 or        1.580 or 1.590 or 1.600 or 1.620 or 1.640 inches;    -   (f) a center having a surface hardness of 65 Shore C or greater,        or 70 Shore C or greater, or a surface hardness within a range        having a lower limit of 55 or 60 or 65 or 70 or 75 Shore C and        an upper limit of 80 or 85 Shore C;    -   (g) a center having a center hardness (H) within a range having        a lower limit of 20 or 25 or 30 or 35 or 45 or 50 or 55 Shore C        and an upper limit of 60 or 65 or 70 or 75 or 90 Shore C; an        outer core layer having a surface hardness (S) within a range        having a lower limit of 20 or 25 or 30 or 35 or 45 or 55 Shore C        and an upper limit of 60 or 70 or 75 or 90 Shore C; and        -   (i) H=S;        -   (ii) H<S, and the difference between H and S is from −15 to            40, preferably from −15 to 22, more preferably from −10 to            15, and even more preferably from −5 to 10; or        -   (iii) S<H, and the difference between H and S is from −15 to            40, preferably from −15 to 22, more preferably from −10 to            15, and even more preferably from −5 to 10;    -   (h) an intermediate layer having a surface hardness (I) that is        greater than both the center hardness of the center (H) and the        surface hardness of the outer core layer (S); I is preferably 40        Shore C or greater or within a range having an lower limit of 40        or 45 or 50 or 85 Shore C and an upper limit of 90 or 93 or 95        Shore C; the Shore D range for I is preferably from 40 to 80,        more preferably from 50 to 70;    -   (i) each core layer having a specific gravity of from 0.50 g/cc        to 5.00 g/cc; preferably from 1.05 g/cc to 1.25 g/cc; more        preferably from 1.10 g/cc to 1.18 g/cc;    -   (j) a center having a surface hardness greater than or equal to        the center hardness of the center;    -   (k) a center having a positive hardness gradient wherein the        surface hardness of the center is at least 10 Shore C units        greater than the center hardness of the center;    -   (l) an outer core layer having a surface hardness greater than        or equal to the surface hardness and center hardness of the        center;    -   (m) a center having a compression of 40 or less;    -   (n) a center having a compression of from 20 to 40; and    -   (o) a golf ball subassembly including the center and the        intermediate core layer has a compression of 30 or greater, or        40 or greater, or 50 or greater, or 60 or greater, or a        compression within a range having a lower limit of 30 or 40 or        50 or 60 and an upper limit of 65 or 75 or 85 or 95 or 105.

In another embodiment, the present invention is directed to a golf ballcomprising a center, an outer core layer, an intermediate core layerdisposed between the center and the outer core layer, and one or morecover layers, wherein the golf ball has one or more of the followingproperties:

-   -   (a) a center having a diameter within a range having a lower        limit of 0.100 or 0.125 or 0.250 inches and an upper limit of        0.375 or 0.500 or 0.750 or 1.000 inches;    -   (b) an intermediate core layer having a thickness within a range        having a lower limit of 0.050 or 0.075 or 0.100 or 0.125 or        0.150 or 0.200 inches and an upper limit of 0.300 or 0.350 or        0.400 or 0.500 inches;    -   (c) an outer core layer having a thickness within a range having        a lower limit of 0.010 or 0.020 or 0.025 or 0.030 or 0.032        inches and an upper limit of 0.070 or 0.080 or 0.100 or 0.150 or        0.310 or 0.440 or 0.560 inches;    -   (d) an outer core layer having a thickness such that a golf ball        subassembly including the center, intermediate core layer, and        core layer has an outer diameter within a range having a lower        limit of 1.000 or 1.300 or 1.400 or 1.450 or 1.500 or 1.510 or        1.530 or 1.550 inches and an upper limit of 1.560 or 1.570 or        1.580 or 1.590 or 1.600 or 1.620 or 1.640 or 1.660 inches;    -   (e) a center having a surface hardness of 65 Shore C or greater,        or 70 Shore C or greater, or greater than 70 Shore C, or 80        Shore C or greater, or a surface hardness within a range having        a lower limit of 70 or 75 or 80 Shore C and an upper limit of 90        or 95 Shore C;    -   (f) an outer core layer having a surface hardness less than or        equal to the surface hardness of the center;    -   (g) an outer core having a surface hardness of 65 Shore C or        greater, or 70 Shore C or greater, or greater than 70 Shore C,        or 80 Shore C or greater, or 85 Shore C or greater;    -   (h) an intermediate core layer having a surface hardness that is        less than both the surface hardness of the center and the        surface hardness of the outer core layer;    -   (i) an intermediate core layer having a surface hardness of less        than 80 Shore C, or less than 70 Shore C, or less than 60 Shore        C;    -   (j) a center specific gravity less than or equal to or        substantially the same as (i.e., within 0.1 g/cc) the outer core        layer specific gravity;    -   (j) a center specific gravity within a range having a lower        limit of 0.50 or 0.90 or 1.05 or 1.13 g/cc and an upper limit of        1.15 or 1.18 or 1.20 g/cc;    -   (k) an outer core layer specific gravity of 1.00 g/cc or        greater, or 1.05 g/cc or greater, or 1.10 g/cc or greater;    -   (l) an intermediate core layer specific gravity of 1.00 g/cc or        greater, or 1.05 g/cc or greater, or 1.10 g/cc or greater;    -   (m) an intermediate core layer specific gravity substantially        the same as (i.e., within 0.1 g/cc) the outer core layer        specific gravity;    -   (n) a center having a surface hardness greater than or equal to        the center hardness of the center;    -   (o) a center having a positive hardness gradient wherein the        surface hardness of the center is at least 10 Shore C units        greater than the center hardness of the center;    -   (p) a center having a compression of 40 or less;    -   (q) a center having a compression of from 20 to 40; and    -   (r) a golf ball subassembly including the center and the        intermediate core layer has a compression of 30 or greater, or        40 or greater, or 50 or greater, or 60 or greater, or a        compression within a range having a lower limit of 30 or 40 or        50 or 60 or 65 and an upper limit of 70 or 75 or 85 or 90 or 95        or 105.

In another embodiment, the present invention is directed to a golf ballcomprising a center, an outer core layer, and one or more cover layers.In a particular aspect of this embodiment, the golf ball has one or moreof the following properties:

-   -   (a) a center having a diameter within a range having a lower        limit of 0.500 or 0.750 or 1.000 or 1.100 or 1.200 inches and an        upper limit of 1.300 or 1.350 or 1.400 or 1.550 or 1.570 or        1.580 inches;    -   (b) a center having a diameter within a range having a lower        limit of 0.750 or 0.850 or 0.875 inches and an upper limit of        1.125 or 1.150 or 1.190 inches;    -   (c) an outer core layer enclosing the center such that the        dual-layer core has an overall diameter within a range having a        lower limit of 1.400 or 1.500 or 1.510 or 1.520 or 1.525 inches        and an upper limit of 1.540 or 1.550 or 1.555 or 1.560 or 1.590        inches, or an outer core layer having a thickness within a range        having a lower limit of 0.020 or 0.025 or 0.032 inches and an        upper limit of 0.310 or 0.440 or 0.560 inches;    -   (d) a center having a center hardness of 50 Shore C or greater,        or 55 Shore C or greater, or 60 Shore C or greater, or a center        hardness within a range having a lower limit of 50 or 55 or 60        Shore C and an upper limit of 65 or 70 or 80 Shore C;    -   (e) a center having a surface hardness of 65 Shore C or greater,        or 70 Shore C or greater, or 75 Shore C or greater, or a surface        hardness within a range having a lower limit of 55 or 60 or 65        or 70 or 75 Shore C and an upper limit of 80 or 85 or 90 or 95        Shore C;    -   (f) an outer core layer having a surface hardness of 50 Shore C        or greater, or 55 Shore C or greater, or 75 Shore C or greater,        or 80 Shore C or greater, or greater than 80 Shore C, or 85        Shore C or greater, or greater than 85 Shore C, or 87 Shore C or        greater, or greater than 87 Shore C, or 89 Shore C or greater,        or greater than 89 Shore C, or 90 Shore C or greater, or greater        than 90 Shore C, or a surface hardness within a range having a        lower limit of 50 or 75 or 80 or 85 Shore C and an upper limit        of 80 or 85 or 90 or 95 Shore C;    -   (g) a center having a surface hardness greater than or equal to        the center hardness of the center;    -   (h) a center having a positive hardness gradient wherein the        surface hardness of the center is at least 10 Shore C units        greater than the center hardness of the center;    -   (i) an outer core layer having a surface hardness greater than        or equal to the surface hardness and center hardness of the        center;    -   (j) an outer core layer having a surface hardness less than the        surface hardness of the center;    -   (k) a core having a positive hardness gradient wherein the        surface hardness of the outer core layer is at least 20 Shore C        units greater, or at least 25 Shore C units greater, or at least        30 Shore C units greater, than the center hardness of the        center;    -   (l) a center having a compression of 40 or less; and    -   (m) a center having a compression of from 20 to 40.

In another particular embodiment, the present invention is directed to agolf ball comprising a core and a cover, wherein the core comprises alayer formed from a first composition comprising an acid copolymer and alayer formed from a second composition comprising an acid copolymer. Thefirst composition and second composition are selected from therelatively soft/low modulus HNP compositions, the relatively hard/highmodulus HNP compositions, and the plasticized acid copolymercompositions disclosed herein. In a particular aspect of thisembodiment, the golf ball has one or more of the following properties:

-   -   (a) a center having a diameter of 0.50 inches or 0.75 inches or        1.00 inches, or 1.25 inches or 1.30 inches, or a diameter within        a range having a lower limit and an upper limit selected from        these values;    -   (b) a center hardness of 50 Shore C or greater, and an outer        core layer surface hardness of 75 Shore C or greater, wherein        the outer core layer surface hardness is optionally greater than        the center hardness;    -   (c) a center hardness of 75 Shore C or greater, and an outer        core layer surface hardness of 50 Shore C or greater, wherein        the outer core layer surface hardness is optionally less than        the center hardness;    -   (d) an inner cover layer having a material hardness less than        the surface hardness of the outer core layer; and    -   (e) at least one of the first composition and the second        composition is at least partially neutralized such that at least        70% of all acid groups present in the composition are        neutralized;    -   (f) at least one of the first composition and the second        composition comprises from 0.5 wt % to 80 wt %, based on the        total weight of the composition, of a plasticizer, wherein the        plasticizer is optionally a fatty acid ester;    -   (g) an additional core layer formed from a rubber composition,        wherein the rubber composition is optionally selected from        polybutadiene and thermosetting polyurethane;    -   (h) an additional core layer formed from a thermoplastic        elastomer composition selected from styrenic block copolymers,        polyolefin blends, elastomeric alloys, thermoplastic        polyurethanes, thermoplastic polyesters, and thermoplastic        polyamides (e.g., Hytrel® thermoplastic polyester elastomers,        commercially available from E. I. du Pont de Nemours and        Company; Kraton® styrenic block copolymers, commercially        available from Kraton Performance Polymers Inc.; Septon®        styrenic block copolymers, commercially available from Kuraray        Co., Ltd.; Riteflex® polyester elastomers, commercially        available from Celanese Corporation; Pelprene® polyester        elastomers, commercially available from Toyobo Co., Ltd.; Pebax®        thermoplastic polyether block amides, commercially available        from Arkema Inc.; and blends of two or more thereof);    -   (i) the core comprises a center formed from the first        composition and an outer core layer formed from the second        composition, wherein the acid copolymer of the first composition        is a relatively soft (or low modulus) HNP, the acid copolymer of        the second composition is a relatively hard (or high modulus)        HNP, and the modulus of the first acid copolymer is at least        10%, or at least 20%, or at least 25% or at least 30%, or at        least 35% less than the modulus of the second acid copolymer;        and    -   (j) the core comprises a center formed from the first        composition and an outer core layer formed from the second        composition, wherein the acid copolymer of the first composition        is a relatively hard (or high modulus) HNP, the acid copolymer        of the second composition is a relatively soft (or low modulus)        HNP, and the modulus of the second acid copolymer is at least        10%, or at least 20%, or at least 25% or at least 30%, or at        least 35% less than the modulus of the first acid copolymer.    -   The weight distribution of cores disclosed herein can be varied        to achieve certain desired parameters, such as spin rate,        compression, and initial velocity.

Golf ball cores of the present invention typically have an overall corecompression of less than 100, or a compression of 87 or less, or anoverall core compression within a range having a lower limit of 20 or 50or 60 or 65 or 70 or 75 and an upper limit of 80 or 85 or 90 or 100 or110 or 120, or an overall core compression of about 80. Compression isan important factor in golf ball design. For example, the compression ofthe core can affect the ball's spin rate off the driver and the feel. Asdisclosed in Jeff Dalton's Compression by Any Other Name, Science andGolf IV Proceedings of the World Scientific Congress of Golf (Eric Thained., Routledge, 2002) (“J. Dalton”), several different methods can beused to measure compression, including Atti compression, Riehlecompression, load/deflection measurements at a variety of fixed loadsand offsets, and effective modulus. For purposes of the presentinvention, “compression” refers to Atti compression and is measuredaccording to a known procedure, using an Atti compression test device,wherein a piston is used to compress a ball against a spring. The travelof the piston is fixed and the deflection of the spring is measured. Themeasurement of the deflection of the spring does not begin with itscontact with the ball; rather, there is an offset of approximately thefirst 1.25 mm (0.05 inches) of the spring's deflection. Very lowstiffness cores will not cause the spring to deflect by more than 1.25mm and therefore have a zero compression measurement. The Atticompression tester is designed to measure objects having a diameter of42.7 mm (1.68 inches); thus, smaller objects, such as golf ball cores,must be shimmed to a total height of 42.7 mm to obtain an accuratereading. Conversion from Atti compression to Riehle (cores), Riehle(balls), 100 kg deflection, 130-10 kg deflection or effective moduluscan be carried out according to the formulas given in J. Dalton.

Golf ball cores of the present invention typically have a coefficient ofrestitution (“COR”) at 125 ft/s of at least 0.75, preferably at least0.78, and more preferably at least 0.79. COR, as used herein, isdetermined according to a known procedure wherein a golf ball or golfball subassembly (e.g., a golf ball core) is fired from an air cannon ata given velocity (125 ft/s for purposes of the present invention).Ballistic light screens are located between the air cannon and the steelplate to measure ball velocity. As the ball travels toward the steelplate, it activates each light screen, and the time at each light screenis measured. This provides an incoming transit time period proportionalto the ball's incoming velocity. The ball impacts the steel plate andrebounds though the light screens, which again measure the time periodrequired to transit between the light screens. This provides an outgoingtransit time period proportional to the ball's outgoing velocity. COR isthen calculated as the ratio of the outgoing transit time period to theincoming transit time period, COR=T_(out)/T_(in).

Cores of the present invention are enclosed with a cover, which may be asingle-, dual-, or multi-layer cover.

Suitable cover layer materials for the golf balls disclosed hereininclude, but are not limited to, ionomer resin and blends thereof(particularly Surlyn® ionomer resin), polyurethanes, polyureas,(meth)acrylic acid, thermoplastic rubber polymers, polyethylene, andsynthetic or natural vulcanized rubber, such as balata. Suitablecommercially available ionomeric cover materials include, but are notlimited to, Surlyn® ionomer resins and DuPont® HPF 1000, HPF 2000, HPFAD 1035, HPF AD 1040, commercially available from E. I. du Pont deNemours and Company; and Iotek® ionomers, commercially available fromExxonMobil Chemical Company.

Particularly suitable outer cover layer materials include relativelysoft polyurethanes and polyureas. When used as cover layer materials,polyurethanes and polyureas can be thermoset or thermoplastic. Thermosetmaterials can be formed into golf ball layers by conventional casting orreaction injection molding techniques. Thermoplastic materials can beformed into golf ball layers by conventional compression or injectionmolding techniques. Light stable polyureas and polyurethanes arepreferred for the outer cover layer material. Additional suitable coverand rubber core materials are disclosed, for example, in U.S. PatentApplication Publication No. 2005/0164810, U.S. Pat. No. 5,919,100, andPCT Publications WO00/23519 and WO00/29129, the entire disclosures ofwhich are hereby incorporated herein by reference. In embodiments of thepresent invention wherein a golf ball having a single layer cover isprovided, the cover layer material is preferably selected frompolyurethane and polyurea. In embodiments of the present inventionwherein a golf ball having a dual cover is provided, the inner coverlayer is preferably a high modulus thermoplastic, and the outer coverlayer is preferably selected from polyurethane and polyurea.

Suitable cover layer materials also include blends of ionomers withthermoplastic elastomers. Suitable ionomeric cover materials are furtherdisclosed, for example, in U.S. Pat. Nos. 6,653,382, 6,756,436,6,894,098, 6,919,393, and 6,953,820, the entire disclosures of which arehereby incorporated by reference. Suitable polyurethane cover materialsare further disclosed in U.S. Pat. Nos. 5,334,673, 6,506,851, 6,756,436,and 7,105,623, the entire disclosures of which are hereby incorporatedherein by reference. Suitable polyurea cover materials are furtherdisclosed in U.S. Pat. Nos. 5,484,870 and 6,835,794, the entiredisclosures of which are hereby incorporated herein by reference.Suitable polyurethane-urea hybrids are blends or copolymers comprisingurethane or urea segments as disclosed in U.S.

Patent Application Publication No. 2007/0117923, the entire disclosureof which is hereby incorporated herein by reference. Additional suitablecover materials are disclosed, for example, in U.S. Patent ApplicationPublication No. 2005/0164810, U.S. Pat. No. 5,919,100, and PCTPublications WO00/23519 and WO00/29129, the entire disclosures of whichare hereby incorporated herein by reference.

The ionomeric composition of the inner cover layer is preferablyselected from:

-   -   (a) a composition comprising a “high acid ionomer” (i.e., having        an acid content of greater than 16 wt %), such as Surlyn 8150®,        a copolymer of ethylene and methacrylic acid, having an acid        content of 19 wt %, which is 45% neutralized with sodium,        commercially available from E. I. du Pont de Nemours and        Company;    -   (b) a composition comprising a high acid ionomer and a maleic        anhydride-grafted non-ionomeric polymer (e.g., Fusabond 572D®, a        maleic anhydride-grafted, metallocene-catalyzed ethylene-butene        copolymer having about 0.9 wt % maleic anhydride grafted onto        the copolymer, commercially available from E. I. du Pont de        Nemours and Company). A particularly preferred blend of high        acid ionomer and maleic anhydride-grafted polymer is a 84 wt        %/16 wt % blend of Surlyn 8150® and Fusabond 572D®. Blends of        high acid ionomers with maleic anhydride-grafted polymers are        further disclosed, for example, in U.S. Pat. Nos. 6,992,135 and        6,677,401, the entire disclosures of which are hereby        incorporated herein by reference;    -   (c) a composition comprising a 50/45/5 blend of Surlyn®        8940/Surlyn® 9650/Nucrel® 960, preferably having a material        hardness of from 80 to 85 Shore C;    -   (d) a composition comprising a 50/25/25 blend of Surlyn®        8940/Surlyn® 9650/Surlyn® 9910, preferably having a material        hardness of about 90 Shore C; and    -   (e) a composition comprising a 50/50 blend of Surlyn®        8940/Surlyn® 9650, preferably having a material hardness of        about 86 Shore C.

Surlyn® 8940 is an E/MAA copolymer in which the MAA acid groups havebeen partially neutralized with sodium ions. Surlyn® 9650 and Surlyn®9910 are two different grades of E/MAA copolymer in which the MAA acidgroups have been partially neutralized with zinc ions. Nucrel® 960 is anE/MAA copolymer resin nominally made with 15 wt % methacrylic acid.Surlyn® 8940, Surlyn® 9650, Surlyn® 9910, and Nucrel® 960 arecommercially available from E. I. du Pont de Nemours and Company.

Non-limiting examples of preferred inner cover layer materials are shownin the Examples below.

The inner cover layer material may include a flow modifier, such as, butnot limited to, Nucrel® acid copolymer resins, and particularly Nucrel®960. Nucrel® acid copolymer resins are commercially available from E. I.du Pont de Nemours and Company.

The outer cover layer is preferably formed from a composition comprisingpolyurethane, polyurea, or a copolymer or hybrid ofpolyurethane/polyurea. The outer cover layer material may bethermoplastic or thermoset.

In a particular embodiment, the cover is a single layer preferablyformed from an ionomeric composition. The single layer cover preferablyhas a surface hardness of 65 Shore D or less, or 60 Shore D or less, or45 Shore D or less, or 40 Shore D or less, or from 25 Shore D to 40Shore D, or from 30 Shore D to 40 Shore D and a thickness within a rangehaving a lower limit of 0.010 or 0.015 or 0.020 or 0.025 or 0.030 or0.055 or 0.060 inches and an upper limit of 0.065 or 0.080 or 0.090 or0.100 or 0.110 or 0.120 or 0.140 inches. The flexural modulus of thecover, as measured by ASTM D6272-98 Procedure B, is preferably 500 psior greater, or from 500 psi to 150,000 psi.

In another particular embodiment, the cover is a two-layer coverconsisting of an inner cover layer and an outer cover layer. The innercover layer is preferably formed from an ionomeric composition andpreferably has a surface hardness of 60 Shore D or greater, or 65 ShoreD or greater, or a surface hardness within a range having a lower limitof 30 or 40 or 55 or 60 or 65 Shore D and an upper limit of 66 or 68 or70 or 75 Shore D, and a thickness within a range having a lower limit of0.010 or 0.015 or 0.020 or 0.030 inches and an upper limit of 0.035 or0.040 or 0.045 or 0.050 or 0.055 or 0.075 or 0.080 or 0.100 or 0.110 or0.120 inches. The inner cover layer composition preferably has amaterial hardness of 95 Shore C or less, or less than 95 Shore C, or 92Shore C or less, or 90 Shore C or less, or has a material hardnesswithin a range having a lower limit of 70 or 75 or 80 or 84 or 85 ShoreC and an upper limit of 90 or 92 or 95 Shore C. The outer cover layer ispreferably formed from a castable or reaction injection moldablepolyurethane, polyurea, or copolymer or hybrid of polyurethane/polyurea.Such cover material is preferably thermosetting, but may bethermoplastic. The outer cover layer composition preferably has amaterial hardness of 85 Shore C or less, or 45 Shore D or less, or 40Shore D or less, or from 25 Shore D to 40 Shore D, or from 30 Shore D to40 Shore D. The outer cover layer preferably has a surface hardnesswithin a range having a lower limit of 20 or 30 or 35 or 40 Shore D andan upper limit of 52 or 58 or 60 or 65 or 70 or 72 or 75 Shore D. Theouter cover layer preferably has a thickness within a range having alower limit of 0.010 or 0.015 or 0.025 inches and an upper limit of0.035 or 0.040 or 0.045 or 0.050 or 0.055 or 0.075 or 0.080 or 0.115inches. The two-layer cover preferably has an overall thickness within arange having a lower limit of 0.010 or 0.015 or 0.020 or 0.025 or 0.030or 0.055 or 0.060 inches and an upper limit of 0.065 or 0.075 or 0.080or 0.090 or 0.100 or 0.110 or 0.120 or 0.140 inches.

In another particular embodiment, the cover is a dual-layer covercomprising an inner cover layer and an outer cover layer. In aparticular aspect of this embodiment, the surface hardness of the outercore layer is greater than the material hardness of the inner coverlayer. In another particular aspect of this embodiment, the surfacehardness of the outer core layer is greater than both the inner coverlayer and the outer cover layer. The inner cover layer preferably has amaterial hardness of 95 Shore C or less, or less than 95 Shore C, or 92Shore C or less, or 90 Shore C or less, or has a material hardnesswithin a range having a lower limit of 70 or 75 or 80 or 84 or 85 ShoreC and an upper limit of 90 or 92 or 95 Shore C. The thickness of theinner cover layer is preferably within a range having a lower limit of0.010 or 0.015 or 0.020 or 0.030 inches and an upper limit of 0.035 or0.045 or 0.080 or 0.120 inches. The outer cover layer preferably has amaterial hardness of 85 Shore C or less. The thickness of the outercover layer is preferably within a range having a lower limit of 0.010or 0.015 or 0.025 inches and an upper limit of 0.035 or 0.040 or 0.055or 0.080 inches.

A moisture vapor barrier layer is optionally employed between the coreand the cover. Moisture vapor barrier layers are further disclosed, forexample, in U.S. Pat. Nos. 6,632,147, 6,932,720, 7,004,854, and7,182,702, the entire disclosures of which are hereby incorporatedherein by reference.

The present invention is not limited by any particular process forforming the golf ball layer(s). It should be understood that thelayer(s) can be formed by any suitable technique, including injectionmolding, compression molding, casting, and reaction injection molding.

When injection molding is used, the composition is typically in apelletized or granulated form that can be easily fed into the throat ofan injection molding machine wherein it is melted and conveyed via ascrew in a heated barrel at temperatures of from 150° F. to 600° F.,preferably from 200° F. to 500° F. The molten composition is ultimatelyinjected into a closed mold cavity, which may be cooled, at ambient orat an elevated temperature, but typically the mold is cooled to atemperature of from 50° F. to 70° F. After residing in the closed moldfor a time of from 1 second to 300 seconds, preferably from 20 secondsto 120 seconds, the core and/or core plus one or more additional core orcover layers is removed from the mold and either allowed to cool atambient or reduced temperatures or is placed in a cooling fluid such aswater, ice water, dry ice in a solvent, or the like.

When compression molding is used to form a center, the composition isfirst formed into a preform or slug of material, typically in acylindrical or roughly spherical shape at a weight slightly greater thanthe desired weight of the molded core. Prior to this step, thecomposition may be first extruded or otherwise melted and forced througha die after which it is cut into a cylindrical preform. It is thatpreform that is then placed into a compression mold cavity andcompressed at a mold temperature of from 150° F. to 400° F., preferablyfrom 250° F. to 350° F., and more preferably from 260° F. to 295° F.When compression molding a core or cover layer of an HNP composition, ahalf-shell is first formed via injection molding and then a corecomprising one or more layers is enclosed within two half shells andthen compression molded in a similar manner to the process previouslydescribed.

Reaction injection molding processes are further disclosed, for example,in U.S. Pat. Nos. 6,083,119, 7,338,391, 7,282,169, 7,281,997 and U.S.Patent Application Publication No. 2006/0247073, the entire disclosuresof which are hereby incorporated herein by reference.

Golf balls of the present invention typically have a compression of 120or less, or a compression within a range having a lower limit of 40 or50 or 60 or 65 or 75 or 80 or 90 and an upper limit of 95 or 100 or 105or 110 or 115 or 120. Golf balls of the present invention typically havea COR at 125 ft/s of at least 0.70, preferably at least 0.75, morepreferably at least 0.78, and even more preferably at least 0.79.

Golf balls of the present invention will typically have dimple coverageof 60% or greater, preferably 65% or greater, and more preferably 75% orgreater. The United States Golf Association specifications limit theminimum size of a competition golf ball to 1.680 inches. There is nospecification as to the maximum diameter, and golf balls of any size canbe used for recreational play. Golf balls of the present invention canhave an overall diameter of any size. The preferred diameter of thepresent golf balls is from 1.680 inches to 1.800 inches. Morepreferably, the present golf balls have an overall diameter of from1.680 inches to 1.760 inches, and even more preferably from 1.680 inchesto 1.740 inches.

Golf balls of the present invention preferably have a moment of inertia(“MOI”) of 70-95 g·cm², preferably 75-93 g·cm², and more preferably76-90 g·cm². For low MOI embodiments, the golf ball preferably has anMOI of 85 g·cm² or less, or 83 g·cm² or less. For high MOI embodiment,the golf ball preferably has an MOI of 86 g·cm² or greater, or 87 g·cm²or greater. MOI is measured on a model MOI-005-104 Moment of InertiaInstrument manufactured by Inertia Dynamics of Collinsville, Conn. Theinstrument is connected to a PC for communication via a COMM port and isdriven by MOI Instrument Software version #1.2.

Thermoplastic layers herein may be treated in such a manner as to createa positive or negative hardness gradient. In golf ball layers of thepresent invention wherein a thermosetting rubber is used,gradient-producing processes and/or gradient-producing rubberformulation may be employed. Gradient-producing processes andformulations are disclosed more fully, for example, in U.S. patentapplication Ser. No. 12/048,665, filed on Mar. 14, 2008; Ser. No.11/829,461, filed on Jul. 27, 2007; Ser. No. 11/772,903, filed Jul. 3,2007; Ser. No. 11/832,163, filed Aug. 1, 2007; Ser. No. 11/832,197,filed on Aug. 1, 2007; the entire disclosure of each of these referencesis hereby incorporated herein by reference.

In addition to the materials disclosed above, any of the core or coverlayers may comprise one or more of the following materials:thermoplastic elastomer, thermoset elastomer, synthetic rubber,thermoplastic vulcanizate, copolymeric ionomer, terpolymeric ionomer,polycarbonate, polyolefin, polyamide, copolymeric polyamide, polyesters,polyester-amides, polyether-amides, polyvinyl alcohols, acrylonitrile-butadiene-styrene copolymers, polyarylate, polyacrylate,polyphenylene ether, impact-modified polyphenylene ether, high impactpolystyrene, diallyl phthalate polymer, metallocene-catalyzed polymers,styrene-acrylonitrile (SAN), olefin-modified SAN,acrylonitrile-styrene-acrylonitrile, styrene-maleic anhydride (S/MA)polymer, styrenic copolymer, functionalized styrenic copolymer,functionalized styrenic terpolymer, styrenic terpolymer, cellulosepolymer, liquid crystal polymer (LCP), ethylene-propylene-diene rubber(EPDM), ethylene-vinyl acetate copolymer (EVA), ethylene propylenerubber (EPR), ethylene vinyl acetate, polyurea, and polysiloxane.Suitable polyamides for use as an additional material in compositionsdisclosed herein also include resins obtained by: (1) polycondensationof (a) a dicarboxylic acid, such as oxalic acid, adipic acid, sebacicacid, terephthalic acid, isophthalic acid or 1,4-cyclohexanedicarboxylicacid, with (b) a diamine, such as ethylenediamine,tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, ordecamethylenediamine, 1,4-cyclohexyldiamine or m-xylylenediamine; (2) aring-opening polymerization of cyclic lactam, such as ε-caprolactam orω-laurolactam; (3) polycondensation of an aminocarboxylic acid, such as6-aminocaproic acid, 9-aminononanoic acid, 11-aminoundecanoic acid or12-aminododecanoic acid; or (4) copolymerzation of a cyclic lactam witha dicarboxylic acid and a diamine. Specific examples of suitablepolyamides include Nylon 6, Nylon 66, Nylon 610, Nylon 11, Nylon 12,copolymerized Nylon, Nylon MXD6, and Nylon 46.

In embodiments of the present invention wherein at least one layer isformed from a rubber composition, suitable rubber compositions includenatural and synthetic rubbers, including, but not limited to,polybutadiene, polyisoprene, ethylene propylene rubber (“EPR”), ethylenepropylene diene rubber (“EPDM”), styrenic block copolymer rubbers (suchas SI, SIS, SB, SBS, SIBS, and the like, where “S” is styrene, “I” isisobutylene, and “B” is butadiene), butyl rubber, halobutyl rubber,copolymers of isobutylene and para-alkylstyrene, halogenated copolymersof isobutylene and para-alkylstyrene, copolymers of butadiene withacrylonitrile, polychloroprene, alkyl acrylate rubber, chlorinatedisoprene rubber, acrylonitrile chlorinated isoprene rubber, andcombinations of two or more thereof. Diene rubbers are preferred,particularly polybutadienes and mixtures of polybutadiene with otherelastomers, and especially 1,4-polybutadiene having a cis-structure ofat least 40%. In a particularly preferred embodiment, the rubbercomposition is a reaction product of a diene rubber, a crosslinkingagent, a filler, a co-crosslinking agent or free radical initiator, andoptionally a cis-to-trans catalyst. The rubber is preferably selectedfrom polybutadiene and styrene-butadiene. The crosslinking agenttypically includes a metal salt, such as a zinc-, aluminum-, sodium-,lithium-, nickel-, calcium-, or magnesium salt, of an unsaturated fattyacid or monocarboxylic acid, such as (meth) acrylic acid. Preferredcrosslinking agents include zinc acrylate, zinc diacrylate (ZDA), zincmethacrylate, and zinc dimethacrylate (ZDMA), and mixtures thereof. Thecrosslinking agent is present in an amount sufficient to crosslink aportion of the chains of the polymers in the composition. Thecrosslinking agent is generally present in the rubber composition in anamount of from 15 to 30 phr, or from 19 to 25 phr, or from 20 to 24 phr.The desired compression may be obtained by adjusting the amount ofcrosslinking, which can be achieved, for example, by altering the typeand amount of crosslinking agent. The free radical initiator can be anyknown polymerization initiator which decomposes during the cure cycle,including, but not limited to, dicumyl peroxide, 1,1-di-(t-butylperoxy)3,3,5-trimethyl cyclohexane, a-a bis-(t-butylperoxy) diisopropylbenzene,2,5-dimethyl-2,5 di-(t-butylperoxy) hexane or di-t-butyl peroxide, andmixtures thereof. The rubber composition optionally contains one or moreantioxidants. Antioxidants are compounds that can inhibit or prevent theoxidative degradation of the rubber. Suitable antioxidants include, forexample, dihydroquinoline antioxidants, amine type antioxidants, andphenolic type antioxidants. The rubber composition may also contain oneor more fillers to adjust the density and/or specific gravity of thecore or cover. Fillers are typically polymeric or mineral particles.Exemplary fillers include precipitated hydrated silica, clay, talc,asbestos, glass fibers, aramid fibers, mica, calcium metasilicate,barium sulfate, zinc sulfide, lithopone, silicates, silicon carbide,diatomaceous earth, polyvinyl chloride, carbonates (e.g., calciumcarbonate and magnesium carbonate), metals (e.g., titanium, tungsten,aluminum, bismuth, nickel, molybdenum, iron, lead, copper, boron,cobalt, beryllium, zinc, and tin), metal alloys (e.g., steel, brass,bronze, boron carbide whiskers, and tungsten carbide whiskers), metaloxides (e.g., zinc oxide, iron oxide, aluminum oxide, titanium oxide,magnesium oxide, and zirconium oxide), particulate carbonaceousmaterials (e.g., graphite, carbon black, cotton flock, natural bitumen,cellulose flock, and leather fiber), microballoons (e.g., glass andceramic), fly ash, regrind, nanofillers and combinations thereof. Therubber composition may also contain one or more additives selected fromfree radical scavengers, accelerators, scorch retarders, coloringagents, fluorescent agents, chemical blowing and foaming agents,defoaming agents, stabilizers, softening agents, impact modifiers,plasticizers, and the like. The rubber composition may also contain asoft and fast agent, such as those disclosed in U.S. patent applicationSer. No. 11/972,240, the entire disclosure of which is herebyincorporated herein by reference. Examples of commercially availablepolybutadienes suitable for use in forming golf ball core layers of thepresent invention include, but are not limited to, Buna CB23,commercially available from LANXESS Corporation; SE BR-1220,commercially available from The Dow Chemical Company; Europrene® NEOCIS®BR 40 and BR 60, commercially available from Polimeri Europa; UBEPOL-BR®rubbers, commercially available from UBE Industries, Ltd.; and BR 01commercially available from Japan Synthetic Rubber Co., Ltd. Suitabletypes and amounts of rubber, crosslinking agent, filler, co-crosslinkingagent, initiator and additives are more fully described in, for example,U.S. Patent Application Publication No. 2004/0214661, 2003/0144087, and2003/0225197, and U.S. Pat. Nos. 6,566,483, 6,695,718, and 6,939,907,the entire disclosures of which are hereby incorporated herein byreference.

In embodiments of the present invention wherein at least one layer isformed from a conventional HNP composition, suitable HNP compositionscomprise an HNP and optionally additives, fillers, and/or melt flowmodifiers. Suitable HNPs are salts of homopolymers and copolymers ofα,β-ethylenically unsaturated mono- or dicarboxylic acids, andcombinations thereof, optionally including a softening monomer. The acidpolymer is neutralized to 70% or higher, including up to 100%, with asuitable cation source. Suitable additives and fillers include, forexample, blowing and foaming agents, optical brighteners, coloringagents, fluorescent agents, whitening agents, UV absorbers, lightstabilizers, defoaming agents, processing aids, mica, talc, nanofillers,antioxidants, stabilizers, softening agents, fragrance components,plasticizers, impact modifiers, acid copolymer wax, surfactants;inorganic fillers, such as zinc oxide, titanium dioxide, tin oxide,calcium oxide, magnesium oxide, barium sulfate, zinc sulfate, calciumcarbonate, zinc carbonate, barium carbonate, mica, talc, clay, silica,lead silicate, and the like; high specific gravity metal powder fillers,such as tungsten powder, molybdenum powder, and the like; regrind, i.e.,core material that is ground and recycled; and nano-fillers. Suitablemelt flow modifiers include, for example, fatty acids and salts thereof,polyamides, polyesters, polyacrylates, polyurethanes, polyethers,polyureas, polyhydric alcohols, and combinations thereof. Suitable HNPcompositions also include blends of HNPs with partially neutralizedionomers as disclosed, for example, in U.S. Patent ApplicationPublication No. 2006/0128904, the entire disclosure of which is herebyincorporated herein by reference, and blends of HNPs with additionalthermoplastic and thermoset materials, including, but not limited to,ionomers, acid copolymers, engineering thermoplastics, fattyacid/salt-based highly neutralized polymers, polybutadienes,polyurethanes, polyesters, thermoplastic elastomers, and otherconventional polymeric materials. Suitable HNP compositions are furtherdisclosed, for example, in U.S. Pat. Nos. 6,653,382, 6,756,436,6,777,472, 6,894,098, 6,919,393, and 6,953,820, the entire disclosuresof which are hereby incorporated herein by reference.

Other preferred materials suitable for use as an additional material ingolf ball compositions disclosed herein include Skypel polyesterelastomers, commercially available from SK Chemicals of South Korea;Septon® diblock and triblock copolymers, commercially available fromKuraray Corporation of Kurashiki, Japan; and Kraton® diblock andtriblock copolymers, commercially available from Kraton Polymers LLC ofHouston, Tex.

Ionomers are also well suited for blending with compositions disclosedherein. Suitable ionomeric polymers include α-olefin/unsaturatedcarboxylic acid copolymer- or terpolymer-type ionomeric resins.Copolymeric ionomers are obtained by neutralizing at least a portion ofthe carboxylic groups in a copolymer of an α-olefin and anα,β-unsaturated carboxylic acid having from 3 to 8 carbon atoms, with ametal ion. Terpolymeric ionomers are obtained by neutralizing at least aportion of the carboxylic groups in a terpolymer of an α-olefin, anα,β-unsaturated carboxylic acid having from 3 to 8 carbon atoms, and anα,β-unsaturated carboxylate having from 2 to 22 carbon atoms, with ametal ion. Examples of suitable α-olefins for copolymeric andterpolymeric ionomers include ethylene, propylene, 1-butene, and1-hexene. Examples of suitable unsaturated carboxylic acids forcopolymeric and terpolymeric ionomers include acrylic, methacrylic,ethacrylic, α-chloroacrylic, crotonic, maleic, fumaric, and itaconicacid. Copolymeric and terpolymeric ionomers include ionomers havingvaried acid contents and degrees of acid neutralization, neutralized bymonovalent or bivalent cations as disclosed herein. Examples ofcommercially available ionomers suitable for blending with compositionsdisclosed herein include Surlyn® ionomer resins, commercially availablefrom E. I. du Pont de Nemours and Company, and Iotek® ionomers,commercially available from ExxonMobil Chemical Company.

Silicone materials are also well suited for blending with compositionsdisclosed herein. Suitable silicone materials include monomers,oligomers, prepolymers, and polymers, with or without adding reinforcingfiller. One type of silicone material that is suitable can incorporateat least 1 alkenyl group having at least 2 carbon atoms in theirmolecules. Examples of these alkenyl groups include, but are not limitedto, vinyl, allyl, butenyl, pentenyl, hexenyl, and decenyl. The alkenylfunctionality can be located at any location of the silicone structure,including one or both terminals of the structure. The remaining (i.e.,non-alkenyl) silicon-bonded organic groups in this component areindependently selected from hydrocarbon or halogenated hydrocarbongroups that contain no aliphatic unsaturation. Non-limiting examples ofthese include: alkyl groups, such as methyl, ethyl, propyl, butyl,pentyl, and hexyl; cycloalkyl groups, such as cyclohexyl andcycloheptyl; aryl groups, such as phenyl, tolyl, and xylyl; aralkylgroups, such as benzyl and phenethyl; and halogenated alkyl groups, suchas 3,3,3-trifluoropropyl and chloromethyl. Another type of suitablesilicone material is one having hydrocarbon groups that lack aliphaticunsaturation. Specific examples include: trimethylsiloxy-endblockeddimethyl siloxane-methylhexenylsiloxane copolymers;dimethylhexenylsiloxy-endblocked dimethyl siloxane-methylhexenylsiloxanecopolymers; trimethylsiloxy-endblockeddimethylsiloxane-methylvinylsiloxane copolymers;trimethylsiloxyl-endblockedmethylphenylsiloxane-dimethylsiloxane-methylvinysiloxane copolymers;dimethylvinylsiloxy-endblocked dimethylpolysiloxanes;dimethylvinylsiloxy-endblocked dimethylsiloxane-methylvinylsiloxanecopolymers; dimethylvinylsiloxy-endblocked methylphenylpolysiloxanes;dimethylvinylsiloxy-endblockedmethylphenylsiloxane-dimethylsiloxane-methylvinylsiloxane copolymers;and the copolymers listed above wherein at least one group isdimethylhydroxysiloxy. Examples of commercially available siliconessuitable for blending with compositions disclosed herein includeSilastic® silicone rubber, commercially available from Dow CorningCorporation of Midland, Mich.; Blensil® silicone rubber, commerciallyavailable from General Electric Company of Waterford, N.Y.; andElastosil® silicones, commercially available from Wacker Chemie AG ofGermany.

Other types of copolymers can also be added to the golf ballcompositions disclosed herein. For example, suitable copolymerscomprising epoxy monomers include styrene-butadiene-styrene blockcopolymers in which the polybutadiene block contains an epoxy group, andstyrene-isoprene-styrene block copolymers in which the polyisopreneblock contains epoxy. Examples of commercially available epoxyfunctionalized copolymers include ESBS A1005, ESBS A1010, ESBS A1020,ESBS AT018, and ESBS AT019 epoxidized styrene-butadiene-styrene blockcopolymers, commercially available from Daicel Chemical Industries, Ltd.of Japan.

Ionomeric compositions used to form golf ball layers of the presentinvention can be blended with non-ionic thermoplastic resins,particularly to manipulate product properties. Examples of suitablenon-ionic thermoplastic resins include, but are not limited to,polyurethane, poly-ether-ester, poly-amide-ether, polyether-urea, Pebax®thermoplastic polyether block amides commercially available from ArkemaInc., styrene-butadiene-styrene block copolymers,styrene(ethylene-butylene)-styrene block copolymers, polyamides,polyesters, polyolefins (e.g., polyethylene, polypropylene,ethylene-propylene copolymers, ethylene-(meth)acrylate,ethylene-(meth)acrylic acid, functionalized polymers with maleicanhydride grafting, epoxidation, etc., elastomers (e.g., EPDM,metallocene-catalyzed polyethylene) and ground powders of the thermosetelastomers.

Also suitable for forming the center and outer core layers are thecompositions having high COR when formed into solid spheres disclosed inU.S. Patent Application Publication No. 2003/0130434 and U.S. Pat. No.6,653,382, the entire disclosures of which are hereby incorporatedherein by reference. Reference is also made to U.S. Patent ApplicationPublication No. 2003/0144087 for various ball constructions andmaterials that can be used in golf ball core, intermediate, and coverlayers.

Additional materials suitable for forming the core layers include thecore compositions disclosed in U.S. Pat. No. 7,300,364, the entiredisclosure of which is hereby incorporated herein by reference. Forexample, suitable core materials include HNPs neutralized with organicfatty acids and salts thereof, metal cations, or a combination of both.In addition to HNPs neutralized with organic fatty acids and saltsthereof, core compositions may comprise at least one rubber materialhaving a resilience index of at least about 40. Preferably theresilience index is at least about 50. Polymers that produce resilientgolf balls and, therefore, are suitable for the present invention,include but are not limited to CB23, CB22, commercially available fromof Bayer Corp. of Orange, Tex., BR60, commercially available fromEnichem of Italy, and 1207G, commercially available from Goodyear Corp.of Akron, Ohio Additionally, the unvulcanized rubber, such aspolybutadiene, in golf balls prepared according to the inventiontypically has a Mooney viscosity of between about 40 and about 80, morepreferably, between about 45 and about 65, and most preferably, betweenabout 45 and about 55. Mooney viscosity is typically measured accordingto ASTM-D1646.

In addition to the above materials, the center can be formed from a lowdeformation material selected from metal, rigid plastics, polymersreinforced with high strength organic or inorganic fillers or fibers,and blends and composites thereof. Suitable low deformation materialsalso include those disclosed in U.S. Patent Application Publication No.2005/0250600, the entire disclosure of which is hereby incorporatedherein by reference.

Examples

It should be understood that the examples below are for illustrativepurposes only. In no manner is the present invention limited to thespecific disclosures herein.

Additional Examples of Suitable HNPs

The HNPs of Table 3 below have been found to be particularly useful asthe relatively soft/low modulus HNP and/or the relatively hard/highmodulus HNP of the present invention.

TABLE 3 Flexural Hardness**, Hardness**, cation Modulus*, Shore C ShoreD Example source psi (18 day) (annealed) 1 Ca/Mg 71,600 88 57 2 Ca/Li70,300 89 58 3 Ca 70,100 92 60 4 Ca/Zn 60,400 88 58 5 Mg 38,300 84 52 6Mg 27,600 84 52 7 Mg 16,300 78 45 8 Mg 10,600 70 40 9 Mg 10,400 69 39*Flexural modulus was measured according to ASTM D790-03 Procedure B.**Hardness was measured according to ASTM D2240.

In embodiments of the present invention directed to a golf ball havingcenter formed from a relatively soft HNP composition, Examples 6-9 areparticularly suitable for use as the relatively soft HNP composition.

In embodiments of the present invention directed to a golf ball havingan outer core layer formed from a relatively soft HNP composition,Examples 5-9 are particularly suitable for use as the relatively softHNP composition.

In embodiments of the present invention directed to a golf ball having acenter formed from a relatively hard HNP composition, Examples 1-6 areparticularly suitable for use as the relatively hard HNP composition.

In embodiments of the present invention directed to a golf ball havingan outer core layer formed from a relatively hard HNP composition,Examples 1-4 are particularly suitable for use as the relatively hardHNP composition.

In embodiments of the present invention directed to a golf ball havingcenter formed from a low modulus HNP composition, Examples 6-9 areparticularly suitable for use as the low modulus HNP composition.

In embodiments of the present invention directed to a golf ball havingan outer core layer formed from a low modulus HNP composition, Examples5-9 are particularly suitable for use as the low modulus HNPcomposition.

In embodiments of the present invention directed to a golf ball having acenter formed from a high modulus HNP composition, Examples 1-6 areparticularly suitable for use as the high modulus HNP composition.

In embodiments of the present invention directed to a golf ball havingan outer core layer formed from a high modulus HNP composition, Examples1-4 are particularly suitable for use as the high modulus HNPcomposition.

Additional Examples of Suitable Ionomeric Cover Layer Compositions

Twelve ionomeric inner cover layer compositions according to the presentinvention were prepared by melt blending Surlyn® 8150 and Fusabond® 572Din a twin screw extruder, at a temperature of at least 450° F. (230°C.). The relative amounts of each component used are indicated in Table4 below.

Flex bars of each blend composition were formed and evaluated forhardness according to ASTM D2240 following 10 days of aging at 50%relative humidity and 23° C. The results are reported in Table 4 below.

TABLE 4 Fusabond ® Shore C Surlyn ® 8150, 572D, Hardness at Example wt %wt % 10 Days 1 89 11 91.2 2 84 16 89.8 3 84 16 90.4 4 84 16 89.6 5 81 1988.9 6 80 20 89.1 7 78 22 88.1 8 76 24 87.6 9 76 24 87.2 10 73 27 86.611 71 29 86.7 12 67 33 84.0

The following commercially available materials were used in the belowexamples:

-   -   A-C® 5120 ethylene acrylic acid copolymer with an acrylic acid        content of 15%,    -   A-C® 5180 ethylene acrylic acid copolymer with an acrylic acid        content of 20%,    -   A-C® 395 high density oxidized polyethylene homopolymer, and    -   A-C® 575 ethylene maleic anhydride copolymer, commercially        available from Honeywell;    -   CB23 high-cis neodymium-catalyzed polybutadiene rubber,        commercially available from Lanxess Corporation;    -   CA1700 Soya fatty acid, CA1726 linoleic acid, and CA1725        conjugated linoleic acid, commercially available from Chemical        Associates;    -   Century® 1107 highly purified isostearic acid mixture of        branched and straight-chain C18 fatty acid, commercially        available from Arizona Chemical;    -   Clarix® 011370-01 ethylene acrylic acid copolymer with an        acrylic acid content of 13% and    -   Clarix® 011536-01 ethylene acrylic acid copolymer with an        acrylic acid content of 15%, commercially available from A.        Schulman Inc.;    -   Elvaloy® AC 1224 ethylene-methyl acrylate copolymer with a        methyl acrylate content of 24 wt %,    -   Elvaloy® AC 1335 ethylene-methyl acrylate copolymer with a        methyl acrylate content of 35 wt %,    -   Elvaloy® AC 2116 ethylene-ethyl acrylate copolymer with an ethyl        acrylate content of 16 wt %,    -   Elvaloy® AC 3427 ethylene-butyl acrylate copolymer having a        butyl acrylate content of 27 wt %, and    -   Elvaloy® AC 34035 ethylene-butyl acrylate copolymer having a        butyl acrylate content of 35 wt %, commercially available        from E. I. du Pont de Nemours and Company;    -   Escor® AT-320 ethylene acid terpolymer, commercially available        from ExxonMobil Chemical Company;    -   Exxelor® VA 1803 amorphous ethylene copolymer functionalized        with maleic anhydride, commercially available from ExxonMobil        Chemical Company;    -   Fusabond® N525 metallocene-catalyzed polyethylene,    -   Fusabond® N416 chemically modified ethylene elastomer,    -   Fusabond® C190 anhydride modified ethylene vinyl acetate        copolymer, and    -   Fusabond® P614 functionalized polypropylene, commercially        available from E. I. du Pont de Nemours and Company;    -   Hytrel® 3078 very low modulus thermoplastic polyester elastomer,        commercially available from E. I. du Pont de Nemours and        Company;    -   Kraton® FG 1901 GT linear triblock copolymer based on styrene        and ethylene/butylene with a polystyrene content of 30% and    -   Kraton® FG1924GT linear triblock copolymer based on styrene and        ethylene/butylene with a polystyrene content of 13%,        commercially available from Kraton Performance Polymers Inc.;    -   Lotader® 4603, 4700 and 4720, random copolymers of ethylene,        acrylic ester and maleic anhydride, commercially available from        Arkema Corporation;    -   Nordel® IP 4770 high molecular weight semi-crystalline EPDM        rubber, commercially available from The Dow Chemical Company;    -   Nucrel® 9-1, Nucrel® 599, Nucrel® 960, Nucrel® 0407, Nucrel®        0609, Nucrel® 1214, Nucrel® 2906, Nucrel® 2940, Nucrel® 30707,        Nucrel® 31001, and Nucrel® AE acid copolymers, commercially        available from E. I. du Pont de Nemours and Company;    -   Primacor® 3150, 3330, 59801, and 59901 acid copolymers,        commercially available from The Dow Chemical Company;    -   Royaltuf® 498 maleic anhydride modified polyolefin based on an        amorphous EPDM, commercially available from Chemtura        Corporation;    -   Sylfat® FA2 tall oil fatty acid, commercially available from        Arizona Chemical;    -   Vamac® G terpolymer of ethylene, methylacrylate and a cure site        monomer, commercially available from E. I. du Pont de Nemours        and Company; and    -   XUS 60758.08L ethylene acrylic acid copolymer with an acrylic        acid content of 13.5%, commercially available from The Dow        Chemical Company.

Various compositions were melt blended using components as given inTable 5 below. The compositions were neutralized by adding a cationsource in an amount sufficient to neutralize, theoretically, 110% of theacid groups present in components 1 and 3, except for example 72, inwhich the cation source was added in an amount sufficient to neutralize75% of the acid groups. Magnesium hydroxide was used as the cationsource, except for example 68, in which magnesium hydroxide and sodiumhydroxide were used in an equivalent ratio of 4:1. In addition tocomponents 1-3 and the cation source, example 71 contains ethyl oleateplasticizer.

The relative amounts of component 1 and component 2 used are indicatedin Table 5 below, and are reported in wt %, based on the combined weightof components 1 and 2. The relative amounts of component 3 used areindicated in Table 5 below, and are reported in wt %, based on the totalweight of the composition.

TABLE 5 Example Component 1 wt % Component 2 wt % Component 3 wt % 1Primacor 5980I 78 Lotader 4603 22 magnesium oleate 41.6 2 Primacor 5980I84 Elvaloy AC 1335 16 magnesium oleate 41.6 3 Primacor 5980I 78 ElvaloyAC 3427 22 magnesium oleate 41.6 4 Primacor 5980I 78 Elvaloy AC 1335 22magnesium oleate 41.6 5 Primacor 5980I 78 Elvaloy AC 1224 22 magnesiumoleate 41.6 6 Primacor 5980I 78 Lotader 4720 22 magnesium oleate 41.6 7Primacor 5980I 85 Vamac G 15 magnesium oleate 41.6 8 Primacor 5980I 90Vamac G 10 magnesium oleate 41.6 8.1 Primacor 5990I 90 Fusabond 614 10magnesium oleate 41.6 9 Primacor 5980I 78 Vamac G 22 magnesium oleate41.6 10 Primacor 5980I 75 Lotader 4720 25 magnesium oleate 41.6 11Primacor 5980I 55 Elvaloy AC 3427 45 magnesium oleate 41.6 12 Primacor5980I 55 Elvaloy AC 1335 45 magnesium oleate 41.6 12.1 Primacor 5980I 55Elvaloy AC 34035 45 magnesium oleate 41.6 13 Primacor 5980I 55 ElvaloyAC 2116 45 magnesium oleate 41.6 14 Primacor 5980I 78 Elvaloy AC 3403522 magnesium oleate 41.6 14.1 Primacor 5990I 80 Elvaloy AC 34035 20magnesium oleate 41.6 15 Primacor 5980I 34 Elvaloy AC 34035 66 magnesiumoleate 41.6 16 Primacor 5980I 58 Vamac G 42 magnesium oleate 41.6 17Primacor 5990I 80 Fusabond 416 20 magnesium oleate 41.6 18 Primacor5980I 100 — — magnesium oleate 41.6 19 Primacor 5980I 78 Fusabond 416 22magnesium oleate 41.6 20 Primacor 5990I 100 — — magnesium oleate 41.6 21Primacor 5990I 20 Fusabond 416 80 magnesium oleate 41.6 21.1 Primacor5990I 20 Fusabond 416 80 magnesium oleate 31.2 21.2 Primacor 5990I 20Fusabond 416 80 magnesium oleate 20.8 22 Clarix 011370 30.7 Fusabond 41669.3 magnesium oleate 41.6 23 Primacor 5990I 20 Royaltuf 498 80magnesium oleate 41.6 24 Primacor 5990I 80 Royaltuf 498 20 magnesiumoleate 41.6 25 Primacor 5990I 80 Kraton FG1924GT 20 magnesium oleate41.6 26 Primacor 5990I 20 Kraton FG1924GT 80 magnesium oleate 41.6 27Nucrel 30707 57 Fusabond 416 43 magnesium oleate 41.6 28 Primacor 5990I80 Hytrel 3078 20 magnesium oleate 41.6 29 Primacor 5990I 20 Hytrel 307880 magnesium oleate 41.6 30 Primacor 5980I 26.8 Elvaloy AC 34035 73.2magnesium oleate 41.6 31 Primacor 5980I 26.8 Lotader 4603 73.2 magnesiumoleate 41.6 32 Primacor 5980I 26.8 Elvaloy AC 2116 73.2 magnesium oleate41.6 33 Escor AT-320 30 Elvaloy AC 34035 52 magnesium oleate 41.6Primacor 5980I 18 34 Nucrel 30707 78.5 Elvaloy AC 34035 21.5 magnesiumoleate 41.6 35 Nucrel 30707 78.5 Fusabond 416 21.5 magnesium oleate 41.636 Primacor 5980I 26.8 Fusabond 416 73.2 magnesium oleate 41.6 37Primacor 5980I 19.5 Fusabond N525 80.5 magnesium oleate 41.6 38 Clarix011536-01 26.5 Fusabond N525 73.5 magnesium oleate 41.6 39 Clarix011370-01 31 Fusabond N525 69 magnesium oleate 41.6 39.1 XUS 60758.08L29.5 Fusabond N525 70.5 magnesium oleate 41.6 40 Nucrel 31001 42.5Fusabond N525 57.5 magnesium oleate 41.6 41 Nucrel 30707 57.5 FusabondN525 42.5 magnesium oleate 41.6 42 Escor AT-320 66.5 Fusabond N525 33.5magnesium oleate 41.6 43 Nucrel 2906/2940 21 Fusabond N525 79 magnesiumoleate 41.6 44 Nucrel 960 26.5 Fusabond N525 73.5 magnesium oleate 41.645 Nucrel 1214 33 Fusabond N525 67 magnesium oleate 41.6 46 Nucrel 59940 Fusabond N525 60 magnesium oleate 41.6 47 Nucrel 9-1 44.5 FusabondN525 55.5 magnesium oleate 41.6 48 Nucrel 0609 67 Fusabond N525 33magnesium oleate 41.6 49 Nucrel 0407 100 — — magnesium oleate 41.6 50Primacor 5980I 90 Fusabond N525 10 magnesium oleate 41.6 51 Primacor5980I 80 Fusabond N525 20 magnesium oleate 41.6 52 Primacor 5980I 70Fusabond N525 30 magnesium oleate 41.6 53 Primacor 5980I 60 FusabondN525 40 magnesium oleate 41.6 54 Primacor 5980I 50 Fusabond N525 50magnesium oleate 41.6 55 Primacor 5980I 40 Fusabond N525 60 magnesiumoleate 41.6 56 Primacor 5980I 30 Fusabond N525 70 magnesium oleate 41.657 Primacor 5980I 20 Fusabond N525 80 magnesium oleate 41.6 58 Primacor5980I 10 Fusabond N525 90 magnesium oleate 41.6 59 — — Fusabond N525 100magnesium oleate 41.6 60 Nucrel 0609 40 Fusabond N525 20 magnesiumoleate 41.6 Nucrel 0407 40 61 Nucrel AE 100 — — magnesium oleate 41.6 62Primacor 5980I 30 Fusabond N525 70 CA1700 soya fatty acid 41.6 magnesiumsalt 63 Primacor 5980I 30 Fusabond N525 70 CA1726 linoleic acid 41.6magnesium salt 64 Primacor 5980I 30 Fusabond N525 70 CA1725 41.6conjugated linoleic acid magnesium salt 65 Primacor 5980I 30 FusabondN525 70 Century 1107 41.6 isostearic acid magnesium salt 66 A-C 512073.3 Lotader 4700 26.7 oleic acid 41.6 magnesium salt 67 A-C 5120 73.3Elvaloy 34035 26.7 oleic acid 41.6 magnesium salt 68 Primacor 5980I 78.3Lotader 4700 21.7 oleic acid 41.6 magnesium salt and sodium salt 69Primacor 5980I 47 Elvaloy AC34035 13 — — A-C 5180 40 70 Primacor 5980I30 Fusabond N525 70 Sylfat FA2 41.6 magnesium salt 71 Primacor 5980I 30Fusabond N525 70 oleic acid 31.2 magnesium salt 10 ethyl oleate 72Primacor 5980I 80 Fusabond N525 20 sebacic acid 41.6 magnesium salt 73Primacor 5980I 60 — — — — A-C 5180 40 74 Primacor 5980I 78.3 — — oleicacid 41.6 A-C 575 21.7 magnesium salt 75 Primacor 5980I 78.3 Exxelor VA1803 21.7 oleic acid 41.6 magnesium salt 76 Primacor 5980I 78.3 A-C 39521.7 oleic acid 41.6 magnesium salt 77 Primacor 5980I 78.3 Fusabond C19021.7 oleic acid 41.6 magnesium salt 78 Primacor 5980I 30 Kraton FG 190170 oleic acid 41.6 magnesium salt 79 Primacor 5980I 30 Royaltuf 498 70oleic acid 41.6 magnesium salt 80 A-C 5120 40 Fusabond N525 60 oleicacid 41.6 magnesium salt 81 Primacor 5980I 30 Fusabond N525 70 erucicacid 41.6 magnesium salt 82 Primacor 5980I 30 CB23 70 oleic acid 41.6magnesium salt 83 Primacor 5980I 30 Nordel IP 4770 70 oleic acid 41.6magnesium salt 84 Primacor 5980I 48 Fusabond N525 20 oleic acid 41.6 A-C5180 32 magnesium salt 85 Nucrel 2806 22.2 Fusabond N525 77.8 oleic acid41.6 magnesium salt 86 Primacor 3330 61.5 Fusabond N525 38.5 oleic acid41.6 magnesium salt 87 Primacor 3330 45.5 Fusabond N525 20 oleic acid41.6 Primacor 3150 34.5 magnesium salt 88 Primacor 3330 28.5 — — oleicacid 41.6 Primacor 3150 71.5 magnesium salt 89 Primacor 3150 67 FusabondN525 33 oleic acid 41.6 magnesium salt 90 Primacor 5980I 55 Elvaloy AC34035 45 oleic acid 31.2 magnesium salt 10 ethyl oleate

Solid spheres of each composition were injection molded, and the solidsphere COR, compression, Shore D hardness, and Shore C hardness of theresulting spheres were measured after two weeks. The results arereported in Table 6 below. The surface hardness of a sphere is obtainedfrom the average of a number of measurements taken from opposinghemispheres, taking care to avoid making measurements on the partingline of the sphere or on surface defects, such as holes or protrusions.Hardness measurements are made pursuant to ASTM D-2240 “IndentationHardness of Rubber and Plastic by Means of a Durometer.” Because of thecurved surface, care must be taken to insure that the sphere is centeredunder the durometer indentor before a surface hardness reading isobtained. A calibrated, digital durometer, capable of reading to 0.1hardness units is used for all hardness measurements and is set torecord the maximum hardness reading obtained for each measurement. Thedigital durometer must be attached to, and its foot made parallel to,the base of an automatic stand. The weight on the durometer and attackrate conform to ASTM D-2240.

TABLE 6 Solid Sphere Solid Sphere Solid Sphere Solid Sphere Ex. CORCompression Shore D Shore C 1 0.845 120 59.6 89.2 2 * * * * 3 0.871 11757.7 88.6 4 0.867 122 63.7 90.6 5 0.866 119 62.8 89.9 6 * * * *7 * * * * 8 * * * * 8.1 0.869 127 65.3 92.9 9 * * * * 10 * * * *11 * * * * 12 0.856 101 55.7 82.4 12.1 0.857 105 53.2 81.3 13 * * * * 140.873 122 64.0 91.1 14.1 * * * * 15 * * * * 16 * * * * 17 0.878 117 60.189.4 18 0.853 135 67.6 94.9 19 * * * * 20 0.857 131 66.2 94.4 21 0.75226 34.8 57.1 21.1 0.729 9 34.3 56.3 21.2 0.720 2 33.8 55.2 22 * * * *23 * * * * 24 * * * * 25 * * * * 26 * * * * 27 * * * * 28 * * * *29 * * * * 30 ** 66 42.7 65.5 31 0.730 67 45.6 68.8 32 ** 100 52.4 78.233 0.760 64 43.6 64.5 34 0.814 91 52.8 80.4 35 * * * * 36 * * * *37 * * * * 38 * * * * 39 * * * * 39.1 * * * * 40 * * * * 41 * * * *42 * * * * 43 * * * * 44 * * * * 45 * * * * 46 * * * * 47 * * * *48 * * * * 49 * * * * 50 * * * * 51 0.873 121 61.5 90.2 52 0.870 11660.4 88.2 53 0.865 107 57.7 84.4 54 0.853 97 53.9 80.2 55 0.837 82 50.175.5 56 0.818 66 45.6 70.7 57 0.787 45 41.3 64.7 58 0.768 26 35.9 57.359 * * * * 60 * * * * 61 * * * * 62 * * * * 63 * * * * 64 * * * *65 * * * * 66 * * * * 67 * * * * 68 * * * * 69 * * * * 70 * * * *71 * * * * 72 * * * * 73 * * * * 74 * * * * 75 * * * * 76 * * * *77 * * * * 78 * * * * 79 * * * * 80 * * * * 81 * * * * 82 * * * *83 * * * * 84 * * * * 85 * * * * 86 * * * * 87 * * * * 88 * * * *89 * * * * 90 * * * * * not measured ** sphere broke during measurement

When numerical lower limits and numerical upper limits are set forthherein, it is contemplated that any combination of these values may beused.

All patents, publications, test procedures, and other references citedherein, including priority documents, are fully incorporated byreference to the extent such disclosure is not inconsistent with thisinvention and for all jurisdictions in which such incorporation ispermitted.

While the illustrative embodiments of the invention have been describedwith particularity, it will be understood that various othermodifications will be apparent to and can be readily made by those ofordinary skill in the art without departing from the spirit and scope ofthe invention. Accordingly, it is not intended that the scope of theclaims appended hereto be limited to the examples and descriptions setforth herein, but rather that the claims be construed as encompassingall of the features of patentable novelty which reside in the presentinvention, including all features which would be treated as equivalentsthereof by those of ordinary skill in the art to which the inventionpertains.

What is claimed is:
 1. A golf ball comprising: (a) a thermoset rubbercenter having a diameter of from 1.200 inches to 1.500 inches, a centerhardness of from 55 Shore C to 75 Shore C, and a surface hardness offrom 45 Shore C to 90 Shore C; (b) a first intermediate layer having athickness of from 0.032 inches to 0.075 inches and formed from acomposition comprising a first acid copolymer of ethylene and anα,β-unsaturated carboxylic acid, optionally including a softeningmonomer selected from the group consisting of alkyl acrylates andmethacrylates; (c) a second intermediate layer having a thickness offrom 0.032 inches to 0.080 inches, a surface hardness greater than orequal to the surface hardness of the center and the center hardness ofthe center, and formed from a composition comprising a second acidcopolymer of ethylene and an α,β-unsaturated carboxylic acid, optionallyincluding a softening monomer selected from the group consisting ofalkyl acrylates and methacrylates; and (d) an outer cover layer; whereinat least one of the first intermediate layer composition and the secondintermediate layer composition is a plasticized composition comprisingfrom 0.5 wt % to 80 wt %, based on the total weight of the composition,of a plasticizer; and wherein at least one of the first intermediatelayer composition and the second intermediate layer composition is atleast partially neutralized such that at least 70% of all acid groupspresent in the composition are neutralized.
 2. The golf ball of claim 1,wherein the first intermediate layer composition is at least partiallyneutralized such that at least 70% of all acid groups present in thefirst intermediate layer composition are neutralized.
 3. The golf ballof claim 1, wherein at least 95% of all acid groups present in the firstintermediate layer composition are neutralized.
 4. The golf ball ofclaim 1, wherein the surface hardness of the second intermediate layeris greater than the surface hardness of the first intermediate layer. 5.The golf ball of claim 1, wherein the plasticizer is selected from thegroup consisting of fatty acid esters.